LEARNING ACTIVITY PACKET MECHATRONICS INDEXING B72001-AA05UEN

Transcription

1 MECHATRONICS LEARNING ACTIVITY PACKET INDEXING B72001-AA05UEN

2 LEARNING ACTIVITY PACKET 5 INDEXING INTRODUCTION Indexing systems are used in mechatronics systems to automatically move parts in a rotary pattern from one station to the next station in the process. This LAP covers different types of indexing systems, their adjustment, programming, and common components used in the systems such as sensors and stepper motors. ITEMS NEEDED Amatrol Supplied 87-MS3 Mechatronics Indexing Station 870-PS7313-AAU, 870-PS7314-AAU, or 870-PS7315-AAU Mechatronics Learning System for Siemens S one per station Siemens S7-300 Programming Cable Siemens Step 7 Programming Software School Supplied Computer with Windows XP Operating System Amatrol or School Supplied Hand Tool Kit or Equivalent FIRST EDITION, LAP 5, REV. B Amatrol, AMNET, CIMSOFT, MCL, MINI-CIM, IST, ITC, VEST, and Technovate are trademarks or registered trademarks of Amatrol, Inc. All other brand and product names are trademarks or registered trademarks of their respective companies. Copyright 2012, 2011 by AMATROL, INC. All rights Reserved. No part of this publication may be reproduced, translated, or transmitted in any form or by any means, electronic, optical, mechanical, or magnetic, including but not limited to photographing, photocopying, recording or any information storage and retrieval system, without written permission of the copyright owner. Amatrol,Inc., 2400 Centennial Blvd., Jeffersonville, IN USA, Ph , FAX

3 TABLE OF CONTENTS SEGMENT 1 STATION OPERATION OBJECTIVE 1 Describe the operation of a indexing material processing station OBJECTIVE 2 Describe the operation of a stepper motor index table SKILL 1 Operate an indexing material processing station SEGMENT 2 COMPONENT ADJUSTMENT OBJECTIVE 3 Describe how to adjust a fi ber optic sensor SKILL 2 Adjust a fi ber optic sensor OBJECTIVE 4 Describe how to adjust a capacitive sensor SKILL 3 Adjust a capacitive sensor SEGMENT 3 STEPPER MOTOR PROGRAMMING OBJECTIVE 5 Describe how to program a stepper motor controller SKILL 4 Program a stepper motor controller OBJECTIVE 6 Describe how to adjust a homing sensor SKILL 5 Adjust a homing sensor SEGMENT 4 MODULE SEQUENCING OBJECTIVE 7 Describe a sequence of operation of a part transfer module SKILL 6 Design a PLC program that sequences a part transfer module OBJECTIVE 8 Describe a sequence of operation of a stepper motor index table SKILL 7 Design a PLC program that sequences stepper motor index table OBJECTIVE 9 Describe a sequence of operation of a parts orientation module SKILL 8 Design a PLC program that sequences a parts orientation module SEGMENT 5 STATION SEQUENCING OBJECTIVE 10 Describe a sequence of operation of an indexing station SKILL 9 Design a PLC program that sequences an indexing station OBJECTIVE 11 Describe the operation of a indexing station with manual/ auto/ reset functions SKILL 10 Design a PLC program that provides manual/ auto/ reset functions for an indexing processing station 3

4 SEGMENT 1 STATION OPERATION OBJECTIVE 1 DESCRIBE THE OPERATION OF A INDEXING MATERIAL PROCESSING STATION Many high-speed machine processes use a rotary indexing machine to rotate the workpieces to various positions, where a different operation can be performed on each workpiece and multiple workpieces can be processed at the same time. These operations might include orientation, drilling, reaming, tapping, polishing, and gauging. DRILLING REAMING TAPPING GAUGING POLISHING INDEXING TABLE ORIENTATION Figure 1. Indexing Material Processing Station 4

5 Rotary indexing tables index parts in specific angular increments and pause at the designated location so that work can be done on the workpiece. The table consists of a circular plate, often metal, and some type of drive to turn it. A typical table contains 4 to 36 nests spaced evenly around its circumference to securely hold the parts during transport and operation. Custom sizes and configurations are available. PLATE NEST DRIVE MOTOR Figure 2. Rotary Indexing Table Rotary indexing tables can be powered by pneumatic, electric, or hydraulic drives. Pneumatic tables are generally used for small to medium loads and are powered by one or more pneumatic cylinders, each of which represents an index. Electrically-powered tables are usually faster than pneumatic tables and can carry heavier loads, although they are often more expensive than pneumatic tables. They are driven by an electric motor and a worm gear or camshaft. When using a worm gear, the motor directly controls the indexing. Modifying the index location only requires a change to the program parameters. When using the camshaft, cams control the number of indexes as well as the acceleration, deceleration, and velocity of the indexing. Modifying the index locations on this table requires changing out the cam, which can be expensive. Hydraulic drive tables use pressurized fluid that transfers rotational kinetic energy. This type of table is used for heavy loads. Several control methods are available for rotating indexing tables. These methods include a ratchet type, servo controlled, or stepper controlled. 5

6 Ratchet controlled indexing tables use a double-acting, piston-type ratchet and gear mechanism. This type of table, which is highly accurate, typically indexes 45, 60, and 90 angles, although customization is available. Figure 3. Ratchet Controlled Indexing Table 6

7 Servo controlled indexing tables are driven by a servo motor. A servo motor can be positioned at any increment under program control. It uses a feedback sensor such as an encoder, which can differentiate a number of discrete positions for each revolution of the motor shaft. It will accurately indicate the position of the motor shaft to the controller. Servo motors are quiet and work well at high speeds. AXIS SERVOMOTOR ENCODER Figure 4. Servo Motor with Encoder 7

8 Stepper controlled indexing tables are driven by stepper motors. Stepper motors are synchronous electric motors that rotate in small increments. They do not use feedback sensors but instead count increments. A typical stepper motor can create 4000 increments per rotation. Stepper motor tables are accurate, simple to position, and fast with smooth motion control. This type of table can often index to almost any angle. A stepper motor index table is an inexpensive method of providing programmable positioning for light-to-medium torque indexing applications. Stepper motors are less expensive than servo motors. They are also very rugged and have excellent holding torque, which eliminates the need for brakes and clutches. STEPPER MOTOR Figure 5. Stepper Controlled Indexing Table Base 8

9 OBJECTIVE 2 DESCRIBE THE OPERATION OF A STEPPER MOTOR INDEX TABLE A typical stepper motor index table consists of a steel or aluminum plate table driven by a programmable stepper motor and a gear drive of some type. When the motor is mounted so the shaft is parallel to the indexing table, the gear drive has to form a right angle to index the table. In this type of application, a worm gear drive is used between the motor and the indexing table. TABLE SHAFT WORM GEAR DRIVE PROGRAMMABLE STEPPER MOTOR Figure 6. Stepper Motor Index Table 9

10 Figure 7 shows a worm gear and worm that is used to convert the stepper motor rotation at a right angle to turn the index table. When the worm turns, it turns a worm gear, which is directly attached to the table. This combination allows higher torque to be transmitted to the indexing table than the stepper motor itself can provide. WORM GEAR WORM Figure 7. Worm and Worm Gear The worm is mounted onto a shaft, which is attached to the stepper motor shaft with a coupling like the beam coupling shown in figure 8. A beam coupling is a reasonably stiff one piece coupling typically used in low torque, low cost applications. BEAM COUPLINGS Figure 8. Beam Coupling 10

11 The stepper motor has a permanent magnet rotating shaft, called a rotor. The body of the motor is surrounded by a series of stator coils that, when energized, create a magnetic field that interacts with the magnet. These coils are turned on and off in sequence causing the rotor to turn forward or backward. To make a stepper motor continue to rotate, the coils have to be turned off and on constantly. Energizing only one coil will make the motor jump to a specific position and stop. ROTOR SHAFT STATOR COILS Figure 9. Diagram of a Stepper Motor 11

12 Figure 10 shows a simplified explanation of the operation of a four-step stepper motor showing a rotor and four stator coils. At position 1 the upper stator coil is energized, holding the rotor in one position. To move the rotor to position 2 the upper stator coil is de-energized and the right stator coil is energized. This pulls the rotor to that stator coil, causing it to move 90 clockwise and align itself with the right coil. The process continues through positions 3 and 4 until the rotor is back to the starting position. + ON - N S UPPER STATOR COIL OFF RIGHT STATOR COIL OFF N OFF OFF ON S N S N 90 S ROTOR - + ROTOR OFF OFF 1 & 5 2 OFF ROTOR LEFT STATOR COIL OFF ROTOR OFF S OFF ON OFF 270 N S N S N + - S ON OFF - + N LOWER STATOR COIL 4 Figure 10. Simplifi ed Explanation of Stepper Motor Operation In reality, stepper motors have many more degrees of rotation per pulse than shown in figure 10. For example, a motor with 5 per pulse (resolution of 5 ) would move its rotor 5 per step requiring 72 pulses (or steps) to complete a 360 rotation. 12

13 Because stepper motors can be controlled by turning the coils on and off, they are easily controlled using digital circuitry. A controller, or computer, simply energizes the coils in a particular pattern and the motor moves accordingly. The computer keeps track of the motor s position by tracking the number of steps given. Programming a stepper motor is typically accomplished in one of two ways: an external motion controller or a built-in programmable motion controller. The external motion controller, also called the integrated control indexer, has the indexer imbedded within the system and can accept commands from the host computer on-line throughout the entire motion process. Communication, operator interface, and I/O functions are separate elements of this type of system. A host computer provides control and management of the motion sequences. I/O AND POWER CONNECTION CONTROLLER PC COMMUNICATION PORT MOTOR Figure 11. Motor with Integrated Indexer 13

14 The built-in programmable motion controller, also called the stand-alone indexer, operates independently of the host computer. Once the program is downloaded through an RS-232/RS-422 serial port, the program can be initiated from operator interfaces, such as a keypad, switch, pushbutton, or through the auxiliary inputs. A typical stand-alone stepper motor has four programmable inputs and outputs. The inputs are controlled by PLC outputs. These inputs and outputs may be used for functions such as homing the indexer, move instructions to go to distinct angles, and a done signal to let the PLC know it is finished moving. The homing sequence of a typical stand-alone stepper motor is set to find the designated Home I/O switch. When the Home signal is given, which is generally on power up, the axis moves at the given maximum velocity in the selected direction until the Home switch is found. It then creeps off the switch at a slow speed in the direction specified until the Home switch turns off. This resets the controller s memory of the motor position to zero. This gives the controller a reference when it moves the indexer. HOMING SWITCH INDEXING TABLE Auxiliary Input PLC Input Stepper Motor Ready PLC Output Stepper Motor Go 45 PLC Output Stepper Motor Go 90 Auxiliary Input Ground +24V STEPPER MOTOR Figure 12. Stand-Alone Stepper Motor with Indexing Table 14

15 SKILL 1 OPERATE AN INDEXING MATERIAL PROCESSING STATION Procedure Overview In this procedure, you will start up and operate the 87-MS3 Indexing station of the 870 Mechatronics System. 1. Locate the Indexing station, shown in figure 13. Figure 13. Indexing Station 2. Verify that this station has been separated from the other stations. If it has not, then proceed with Step 3 to separate it from the other stations. If it has, then proceed to Step 4. 15

16 3. Perform the following substeps to separate the Indexing station from the other stations. A. Remove the power cord from the wall outlet. B. Remove the adjoining unit s power cord. C. Remove the adjoining unit s pneumatic hose. D. Disconnect the 9-pin to 9-pin cable from the other unit(s). E. Loosen the connecting fasteners that hold the work surfaces together by turning the wing nuts CCW. F. Push the station away from the other stations to give yourself room to work. 4. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 14. Mechatronics Safety Check 16

17 5. Perform the following substeps to mount the red plastic parts bin to the station. This bin is used when the station is separated from the other stations to catch the parts as they are pushed off the indexing table by the parts transfer module. A. Obtain the red plastic parts bin, mounting bracket, (2) 1/4-20 x 1/2 thumbscrews, and 2 T-nuts, shown in figure 15. BIN BRACKET THUMBSCREWS T-NUTS Figure 15. Parts Bin, Mounting Bracket, and Mounting Hardware 17

18 B. Loosen the end cap on the right side of the work surface (as you are facing the station), by prying it off, as shown in figure 16. A screwdriver may be required as the end cap may have a tight fit. Figure 16 shows the back end cap loosened. END CAP Figure 16. Loosen End Cap C. Slide the two T-nuts along the inside of the aluminum extrusion so that they are positioned in line with the end of the transfer cylinder. T-NUTS Figure 17. Position the T-Nuts 18

19 D. Position the mounting bracket so it is inline with the work fixture and the transfer cylinder as shown in figure 18. The milled portion of the bracket faces the indexing table. E. Use a screwdriver to position the T-nuts so they are in line with the holes in the mounting bracket. F. Insert the thumbscrews through the outside of the bracket so that the threads engage the T-nuts, and tighten the thumbscrews by turning them CW until snug so the bracket is secure. The T-nuts have a tendency to angle back away from vertical, so this step may take several tries. TRANSFER Figure 18. Mount the Parts Bin Mounting Bracket 19

20 G. Attach the parts bin to the top of the mounting bracket, as shown in figure 19. Figure 19. Parts Bin Mounted on Bracket 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s electrical power cable into a wall outlet. 8. Perform the following substeps to power up the 87-MS3 Indexing station. A. Place the Mode selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on the air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. F. Turn the station s Main Power switch to the On position. 9. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 20

21 10. Perform the following substeps to open project Indexing Station. A. Click the Open Project/Library button. The Open Project/Library dialog should open. B. Locate project Indexing. The project Indexing is provided on a supplemental disk. If it is not listed on the dialog, click the Browse button on the dialog to view the projects located in the S7Proj folder. C. Double-click the Indexing icon to open the project. D. Select Expand All from View menu to expand the project s contents. The option is Expand All if using STEP 7 Version 5.2 or Show All Levels if using STEP 7 Version Perform the following substeps to download the PLC project named Indexing to the PLC. A. Place the PLC s Mode Selector switch in the RUN position. B. Reset the PLC. C. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. D. Click Yes on the dialog to complete a warm restart. 12. Press the Output Power pushbutton to enable the PLC s outputs. The indexing table will home at this time. 21

22 13. Verify the Pulse Width Modulator shown in figure 20 is switched to the Manual position and the potentiometer is turned fully CW. NOTE The Pulse Width Modulator (PWM) shown in figure 20 is used only with a future Analog option and will not be used with this curriculum. However, if the potentiometer is not turned fully CW, the program will fault due to a timing error. Figure 20. Pulse Width Modulator PULSE WIDTH MODULATOR 22

23 14. Turn the Mode Selector switch to Reset. This will home all of the actuators. Once these are all reset, the Start pushbutton light should be off. 15. Turn the Mode Selector switch back to Manual. 16. Place a good valve body in the initial location on the indexing table in the orientation shown in figure 20. NOTE A good valve body is one that has ports drilled in it and measures 0.94 in. to 1 in. in height. Ask your instructor for assistance in identifying these in in. Figure 21. Valve Body Orientation for Indexing Table 23

24 17. Perform the following substeps to move the station through its sequence of operations using the single step, manual mode for a part that is oriented correctly. Observe the system and notify your instructor of anything that does not function properly. A. Press and release the Start pushbutton to activate step 1 of the sequence. After receiving the input signal from the capacitive proximity (part present) sensor, the PLC sends a signal to the stepper motor. The Start pushbutton indicator should be off before you press it and on solid through the step. It will turn off as soon as the step is complete. You should see the following sequence occur. 1. Index Stepper motor 45 to fiber optic sensor 2. Index Stepper motor 135 to transfer cylinder 3. Extend Transfer cylinder 4. Retract Transfer cylinder 5. Cycle ends B. Press and release the Start pushbutton to activate step 2 of the sequence. The fiber optic sensor should see its light through the port in the valve body, which indicates that the valve body is oriented correctly. The PLC will then send two signals to the stepper motor: one to index 45 and one to index 90 for a total of 135. This will rotate the valve body to the part transfer module. C. Press and release the Start pushbutton to activate step 3 of the sequence. Once the part reaches the part transfer module, the part transfer cylinder will extend to push the valve body off the index table and into the bin. D. Press and release the Start pushbutton to activate step 4 of the sequence. After the cylinder extends and pushes off the valve body, it retracts, finishing the cycle. 24

25 18. Perform the following substeps to move the station through its sequence of operation using single step, manual mode for a part that is oriented incorrectly. A. Place a good valve body in the initial location on the indexing table in the orientation shown in figure 22. This orientation is upside down from the orientation in Step in in. Figure 22. Valve Body Orientation for Indexing Table 25

26 B. Press and release the Start pushbutton to activate step 1 of this sequence. This step is the same as in substep 16A, the PLC sends a signal to the stepper motor. You should see the following steps occur. 1. Index Stepper motor Index Stepper motor Retract Y-axis 4. Close Gripper/Start time delay 5. Extend Y-axis 6. Rotate Gripper Retract Y-axis 8. Open Gripper/Start time delay 9. Extend Y-axis 10. Index Stepper motor Extend Transfer cylinder 12. Retract Transfer cylinder 13. Cycle ends C. Press and release the Start pushbutton to activate step 2 of the sequence. The fiber optic sensor should not see its light through the port in the valve body, which indicates that the valve body is not oriented correctly. The PLC will then send a signal to the stepper motor to index the table 45, which rotates the valve body to the pick and place pneumatic manipulator. NOTE The fiber optic sensor can see through the acrylic valve bodies, so proper orientation is very important. D. Press and release the Start pushbutton to activate step 3 of the sequence. Once the valve body reaches the manipulator, its cylinder retracts down, positioning the gripper on either side of the valve body. E. Press and release the Start pushbutton to activate step 4 of the sequence. After the gripper retracts down, the gripper actuates and grips the valve body. F. Press and release the Start pushbutton to activate step 5 of the sequence. Once the gripper grips the valve body, the manipulator cylinder extends. G. Press and release the Start pushbutton to activate step 6 of the sequence. After the cylinder extends, the gripper rotates 180 so the valve body is right side up. H. Press and release the Start pushbutton to activate step 7 of the sequence. Once the gripper rotates, the cylinder retracts down again. 26

27 I. Press and release the Start pushbutton to activate step 8 of the sequence. After the cylinder retracts, the gripper opens to release the valve body. J. Press and release the Start pushbutton to activate step 9 of the sequence. Once the gripper opens, the manipulator cylinder extends again. K. Press and release the Start pushbutton to activate step 10 of the sequence. After the cylinder extends, the PLC sends a signal to the stepper motor to rotate 90. This will rotate the valve body to the part transfer module. L. Press and release the Start pushbutton to activate step 11 of the sequence. Once the part reaches the part transfer module, the part transfer cylinder will extend to push the valve body off the index table and into the bin. M. Press and release the Start pushbutton to activate step 12 of the sequence. After the cylinder extends and pushes off the valve body, it retracts, finishing the cycle. 19. Place a good valve body in the initial location on the indexing table. 20. Turn the Mode Selector switch to Auto. If you successfully single-stepped through the complete sequence and all of the actuators are back in their home positions, the Start pushbutton lamp should be off and you can move on to Step 21. If it is not, perform Step 20 to reset the actuators. 21. Perform the following substeps to reset the actuators and put the system in Auto mode. A. Remove the valve body from the indexing table. B. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. C. Place the valve body back in the initial location on the indexing table. D. Turn the Mode Selector switch to Auto. The Start pushbutton lamp should be off at this time, indicating that the actuators are reset and the station is ready to run an automatic cycle. 22. Press the Start pushbutton to start the automatic cycle. Observe the station while it goes through one cycle. It is programmed to run through one cycle and then stop. The Start pushbutton indicator is on solid during the cycle to indicate that the station is operating. 23. Perform the following substeps to record the operation of the station when the Stop pushbutton is pressed. This will show you how the system is programmed to respond to the stop pushbutton. A. Place a good valve body in the initial location on the indexing table. B. Press the Start pushbutton to start the cycle again. C. During the middle of the cycle, press the red Stop pushbutton to stop the system. 27

28 The Stop pushbutton is programmed as a halt function, which means the station will complete its current sequence step and stop with all power remaining on. You should see the operation continue to the end of the current sequence step. D. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 23. Operator Panel Indicators Since this is a halt, the machine can resume operation, so you should observe that output power remains on and the Start pushbutton lamp turns off. It has been programmed to do so when the station is in the auto mode and ready to run its automatic cycle. The Emergency Stop lamp should be off because it is not pressed. E. Observe the PLC processor s status indicators and record their status. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 24. PLC Processor Status Indicators You should see that the PLC processor s DC5V and Run indicator lights are on, because the station is halted and ready to resume automatic operation. F. Observe the PLC I/O modules status indicators to see if some of them are on. You should see various input and output indicators on. Which ones will depend on the point in the operation at which the Stop button was pushed. 28

29 24. Press the Start pushbutton to restart the system. It should continue where it left off and finish the cycle. The Start indicator lamp should be on solid until the cycle is finished. NOTE If any actuators are manually moved while the system is halted, the station may not resume operation when the start pushbutton is pressed. If this occurs, go to Step 25 and restart the system. 25. Repeat Steps 22 and 23 three times, stopping the cycle with the Stop pushbutton at different times to observe how it reacts. Remember to place a valve body in the initial location on the indexing table before each new cycle. 26. Perform the following substeps to restart the station IF any of the inputs change after the Stop button is pressed, otherwise skip to Step 26. If any of the inputs were changed, like a part removed from the grippers, or a cylinder moved physically, the system cannot be restarted with the Start pushbutton. This is because the input signals will no longer match those needed to begin the sequence. This is a protective measure to prevent damage to the system. A. Remove any valve bodies that are on the indexing table or in the gripper. B. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. C. Place a good valve body in the initial location on the indexing table. D. Turn the Mode Selector switch back to Auto. E. Press the Start pushbutton to start the automatic cycle. Observe the system while it goes through the cycle before continuing to the next step. 27. Perform the following substeps to record the operation of the station when the Emergency Stop pushbutton is pressed. This step will show you how the system is programmed to respond to the emergency stop pushbutton. A. Place a good valve body in the initial location on the indexing table. B. Press the Start pushbutton to start the cycle again. C. During the middle of the cycle, press the red Emergency Stop pushbutton to stop the system. 29

30 D. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 25. Operator Panel Indicators Since this is an emergency stop, the machine cannot resume operations. You should observe that the output power is off, the start pushbutton lamp is off because output power is off, and the Emergency Stop lamp is on. The Emergency Stop function does not remove the air supply. E. Observe the PLC processor s status indicators and record their status. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 26. PLC Processor Status Indicators You should see the PLC processor s DC5V and Run indicator lights on. F. Observe the PLC I/O modules status indicators to see if some of them are on. You should see various input indicators on, but all output indicators are off. This is because the Emergency stop circuit breaks power to the Output Power contactor, which drops all output power. 28. Perform the following substeps to recover from the Emergency Stop. A. Pull the Emergency Stop button out. B. Remove any valve bodies that are on the indexing table or in the gripper. C. Press the Output Power button to turn the outputs back on. You should hear the contactor pull in to re-establish the power to the outputs. D. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. E. Place a good valve body in the initial location on the indexing table. F. Turn the Mode Selector switch back to Auto. G. Press the Start pushbutton to start the automatic cycle. 30

31 Observe the system while it goes through the cycle before continuing to the next step. 29. Perform the following substeps to record the operation of the station when the station experiences a power loss. This will show you how the station is programmed to respond to a power loss. A. Place a good valve body in the initial location on the indexing table. B. Press the Start pushbutton to start the cycle again. C. During the middle of the cycle, turn the Main Power switch to Off to remove power to the system. D. Observe the operator panel indicators and record their status in the table below. OPERATOR PANEL INDICATORS Indicator Status (On/Off/Blinking) Output Power Lamp Start Lamp Emergency Stop Lamp Figure 27. Operator Panel Indicators Because this is a power loss, simulated by turning the Main Power switch off, power to everything past the Main Power switch is turned off. You should see all operator panel indicator lamps and PLC indicators are off, but you will notice that the pneumatic power remains. You should also have seen any cylinders complete their strokes because they are pneumatically-operated. E. Observe the PLC processor s status indicators and record which indicators are on. SF DC5V FRCE RUN STOP PLC PROCESSOR STATUS INDICATORS Indicator Status (On/Off) Figure 28. PLC Processor Status Indicators You should see all indicators off because there is no power to the PLC. F. Observe the PLC I/O modules status indicators to see if some of them are on. Again, you should see all input and output indicators off because the modules have no power. 31

32 30. Perform the following substeps to recover from the power loss. A. Remove any valve bodies that are on the indexing table or in the gripper. B. Place the Mode Selector switch in the Manual position. C. Turn the station s Main Power switch to the On position. D. Press the Output Power pushbutton to enable the PLC s outputs You should also hear the contactor located next to the PLC module pull in. The Start pushbutton should be off because the station is in Manual mode and has not been reset. E. Turn the Mode Selector switch to Reset. This will move all of the actuators back to their home positions. F. Place a valve body in the initial location on the indexing table. G. Turn the Mode Selector switch to Auto. The Start indicator should be off indicating it is ready to run. H. Press the Start pushbutton to restart the operation. You should see the system run through its sequences. I. Run the system through two complete cycles to make sure it has recovered correctly. Remember to place a valve body in the initial location on the indexing table before each new cycle. 31. Perform the following substeps to shut down the 87-MS3 Indexing station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS3 s Main Power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 32

33 SEGMENT 1 SELF REVIEW 1. Rotary indexing tables index parts in specific increments and pause at the designated location. 2. Rotary indexing tables can be powered by pneumatic, electric, or drives. 3. A stepper motor index table is an inexpensive method of providing programmable positioning for torque indexing applications. 4. Stepper motors have a permanent rotating shaft, also know as the rotor. 5. A typical stand-alone stepper motor has programmable inputs and outputs. 6. The sequence of a stepper motor resets the controller s memory of the motor position to zero. 33

34 SEGMENT 2 COMPONENT ADJUSTMENT OBJECTIVE 3 DESCRIBE HOW TO ADJUST A FIBER OPTIC SENSOR Fiber optic sensors are photoelectric sensors with fiber optic filaments attached to the sensor to send and receive light. The optical fibers are very small and flexible and can be positioned in sensing locations that are not easily accessible. Figure 29. Fiber Optic Sensor 34

35 One typical application of a fiber optic sensor is go no-go testing. In this application, the sensor s small beam width can be used to detect the presence of features or perform measurements. The application shown in figure 30 uses a through beam fiber optic sensor to measure the orientation of a valve body. When there is a clear path between the emitter and receiver, the sensor turns on. TOP VIEW BEAM BLOCKED AS PART PASSES THROUGH AMPLIFIER EMITTER RECEIVER PART SIDE VIEW EMITTER RECEIVER PART BEAM PASSES THROUGH PART AMPLIFIER Figure 30. Fiber Optic Sensor Application The part shown in figure 30 blocks the beam as it passes through it to the inspection point (designated hole location). Once it reaches the inspection point, if the hole in the part is in the designated location, then the beam will pass through the hole. This creates a clear path between the emitter and receiver. This causes the sensor to turn on indicating a good part. If, however, the hole location is off or there is no hole, the sensor will not turn on, indicating a bad part. 35

36 Many sensors, including fiber optic sensors, output a very low signal level, so they require an amplifier, which receives a small signal from the sensor and outputs a larger signal that closely matches the characteristics of the original signal. Amplifiers typically have a potentiometer to adjust the sensitivity along with LEDs that indicate a weak signal and the output status. GREEN LED RED LED SENSITIVITY INDICATOR POTENTIOMETER MODE SELECTOR Figure 31. Fiber Optic Sensor Amplifi er Fiber optic sensors have two types of adjustments: sensitivity and physical location. Adjusting the sensitivity of a fiber optic signal requires turning the potentiometer either toward the + or higher number for increased sensitivity or toward the - or lower number for decreased sensitivity. Many amplifiers potentiometers have only 3 turns, so there is not a lot of adjustment available. To adjust the sensitivity of a typical amplifier that is set to light on (sensor energizes when the receiver senses the light output by the emitter), with no part present, turn the potentiometer (some require a small screwdriver) until the red indicator light turns on, showing that the receiver is seeing the light put out by the emitter. Observe the green indicator light, which is the signal strength indicator. If it is flashing, the signal is weak and the gain (or strength) should be increased. To increase gain, turn the potentiometer toward + or a higher number until the green signal strength indicator is solid. The sensitivity adjustment can be visually checked by reading the sensitivity indicator. 36

37 If the part being sensed is not opaque, then place a part between the emitter and receiver to determine if the sensor can see through the part. If the red indicator light is on when the part is present, the sensitivity needs to be decreased until the light goes off. Then the sensitivity will need to be checked again without the part present to make sure it has not been decreased too much. This process may take some trial and error to get the sensitivity set just right. The Mode selector on the amplifier allows the mode to be changed to Set, L-ON, or D-ON. Set causes the light source to flash and is used to align the emitter and receiver. L-ON sets the Output transistor to turn on when light is received (Light-ON). D-ON sets the Output transistor to turn on the light is not received (Dark-ON). There are two physical adjustments that must be made to a fiber optic sensor to be taken into consideration. The first is to line up the sensing heads up so that the emitter and receiver are directly across from one another, which will be indicated by the output status light (in the case of a light-on sensor the status light would be on). The second is to properly adjust the location of the sensor to detect the required feature. In the example of figure 32, the sensor is positioned to sense the presence of a through hole in a part. LINE UP SENSING HEADS ADJUST TO SENSE FEATURE ADJUST SENSOR LOCATION TO FEATURE THROUGH HOLE PART ADJUST SENSOR LOCATION TO FEATURE Figure 32. Sensor Adjustments 37

38 SKILL 2 ADJUST A FIBER OPTIC SENSOR Procedure Overview In this procedure, you will adjust the fiber optic sensor on the 87-MS3 Indexing station. This will familiarize you with the steps necessary to properly adjust a thru-beam fiber optic sensor to the feature being tested. 1. Locate the Indexing station. 2. Verify that this station has been separated from the other stations. If it has not, then separate them. 3. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 33. Mechatronics Safety Check 4. Plug the station s electrical power cable into a wall outlet. 5. Perform the following substeps to power up the 87-MS3 Indexing station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Turn the station s Main Power switch to the On position. 38

39 6. Perform the following substeps to set the sensitivity on the fiber optic sensor. A. Locate the fiber optic amplifier, shown in figure 34. GREEN LED RED LED POTENTIOMETER Figure 34. Fiber Optic Amplifi er B. Obtain a small, flat bladed screwdriver and turn the potentiometer, shown in figure 34, completely to the left, toward the number 1. This sets the sensitivity to its lowest setting. C. Verify that there is not a part between the fiber optic emitter and receiver. D. Using the screwdriver, adjust the sensitivity potentiometer slowly toward the number 3, until the red indicator light, shown in figure 34, turns on. E. Observe the green indicator light at this time. This is the signal strength indicator. If this light is flashing, then turn the potentiometer further toward the number 3 until it stops flashing. 39

40 F. Place a good acrylic valve body right side up (with the 0.50 side on the bottom) on the indexing table in the fiber optic sensor location. The sensor s beam should go through the port and into the receiver. The red indicator light should be on. This shows you how the sensor reacts when the beam from the emitter reaches the receiver. EMITTER FIBEROPTIC SENSOR RECEIVER 0.50 ACRYLIC VALVE BODY BEAM PASSES THROUGH PART FROM THE EMITTER TO THE RECEIVER RED LIGHT ON AMPLIFIER Figure 35. Beam Passes Through Part G. Turn the valve body over, so that it is upside down. The sensor should not see itself and the red indicator light should be off. If the light is still on, either the physical adjustment is such that it will sense the hole in the valve body in both orientations, or the sensitivity is set so high that it is actually seeing through the acrylic. One way to test this is to try a known defective acrylic valve body. If the indicator light is off with a known defective body, then you know the sensitivity is good. On the other hand, if it is on, then you know it is seeing through the acrylic and the sensitivity needs to be decreased. H. Once you have set the sensitivity correctly, go to Step 7 to perform the physical adjustment. NOTE The fiber optic sensing heads on the 87-MS3 are mounted in the same bracket, so it will not be necessary to adjust them so the emitter and receiver are aligned. 40

41 7. Perform the following substeps to adjust the height of the fiber optic sensor module. A. Place a known good acrylic valve body upside down (0.50 side up) in the fiber optic sensing module. B. Verify the red indicator light on the amplifier is off. C. Mark the location of the fiber optic sensor s bracket on its support post with a pencil. D. Obtain a 7/8 in. hex wrench. E. Loosen the button head cap screws holding the fiber optic sensor bracket, shown in figure 36, enough so that you can slide the bracket up and down. FIBEROPTIC SENSOR BUTTON HEAD CAP SCREWS ACRYLIC VALVE BODY 7/8 in. HEX WRENCH RED LIGHT OFF AMPLIFIER Figure 36. Adjust Fiber Optic Sensor Location F. Adjust the bracket height so that the sensor can see itself through the hole in the upside down valve body. G. Tighten the bracket screws. H. Turn the valve body over so that it is right-side up and see if the sensor sees itself or not. There is a small chance that it can see itself due to the size of the holes in the body. I. Move the sensor back to the original location as marked in substep 7C. In this location, when the valve body is placed right-side up (0.50 side down), the beam passed through the port (red LED on), but when the valve body is turned over (0.50 side up), then the beam does not pass through the part (red LED off). J. Tighten the mounting screws securely. 8. Perform the following substeps to shut down the 87-MS3 Indexing station. A. Turn the 87-MS3 s Main Power switch to Off. B. Perform a lockout/tagout on the system s electrical power source. 41

42 OBJECTIVE 4 DESCRIBE HOW TO ADJUST A CAPACITIVE SENSOR A capacitive proximity sensor, like the one shown in figure 37, uses the principle of capacitance to sense the presence of an object. It creates an electrostatic field that is used to sense when a part comes into range. C.P. Figure 37. Capacitive Proximity Sensor 42

43 A capacitive proximity sensor can sense both metallic and nonmetallic objects. One application of a capacitive proximity sensor is to detect the presence of plastic parts on an indexing table, as shown in figure 38. Figure 38. Capacitive Proximity Sensor Used with Indexing Table Some capacitive sensors have a built-in sensitivity adjustment, which can allow the operator to alter the electric field strength emitted by the sensor. Too much sensitivity can cause problems. If the sensor is used to detect a part, a high sensitivity may cause the sensor to detect the part when it is not present because the high signal strength detects the surrounding fixtures. Likewise, if the sensitivity is decreased too much, the sensor may not see the part when it should. If both non-metallic and metallic parts are to be detected by the sensor, the sensitivity must be adjusted for both materials. It is easier for the sensor to detect a metallic object than a non-metallic object. The sensitivity must be adjusted so that both materials are detected, but not sensitive enough that it never turns off when a metallic part is lifted off of the fixture. A capacitive sensor can also be adjusted so the sensor can see through a lower dielectric material (an electrical insulating material) and detect a higher dielectric material on the other side. 43

44 For example, the sensitivity can be adjusted to see through the wall of a plastic container or glass window and detect a higher dielectric constant material such as a liquid on the other side, as shown in figure 39. SENSOR Figure 39. Detection Through a Material This is accomplished by placing an empty container in front of the sensor, and reducing the sensitivity until the sensor does not see the object. When the liquid, powder, or granules are added to the container, they should be detected by the sensor as long as their dielectric constant is higher than the containers. The steps to adjust the sensitivity of a capacitive sensor used to detect both metallic and non-metallic objects are: Step 1: Place a metallic target in front of the sensor The metallic target should be placed on the fixture in front of the sensor as shown in figure 40. The metallic target is used first because it is the easiest to detect. SENSOR METALLIC TARGET Figure 40. Metallic Target Placement 44

45 Step 2: Adjust the sensitivity until the target is just detected The sensitivity adjustment screw should first be turned to decrease sensitivity until the target is not detected. It should then be increased until the target is just detected. The LED on the sensor or the PLC input status indicator can be used to monitor the sensor s status, as they turn on when the sensor is activated. INDICATOR LIGHT ADJUSTMENT SCREW Figure 41. Adjust Sensitivity 45

46 Step 3: Place a non-metallic target in front of the sensor Replace the metallic target with the non-metallic target. The target should not be detected with the current setting. SENSOR NON-METALLIC TARGET Figure 42. Non-Metallic Target Placement Step 4: Increase the sensitivity until the target is just detected Slowly increase the sensitivity until the non-metallic target is just detected. Remove and replace the target several times to verify that it is detected consistently. If it is not, increase the sensitivity slightly (1/4 turn) and repeat the procedure to verify that it is detected consistently. Step 5: Verify that neither target is detected as it is lifted off of the fixture Run the system several times with each type of target and verify that the sensor turns on and off correctly for both types of targets. 46

47 SKILL 3 ADJUST A CAPACITIVE SENSOR Procedure Overview In this procedure, you will adjust the sensitivity of a capacitive sensor on the 87-MS3 Indexing station. This will familiarize you with the station and with adjusting a capacitive sensor. 1. Locate the 87-MS3 Indexing station. This is the station that has a capacitive sensor. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 43. Mechatronics Safety Check 4. Connect an air supply line to the station s air manifold quick connect. 5. Plug the station s power cable into a wall outlet. 6. Perform the following substeps to power up the station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on the air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. F. Turn the station s Main Power Switch to the On position. 7. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. 47

48 C. Start the SIMATIC Manager. 8. Perform the following substeps to open project Indexing. A. Click the Open Project/Library button. The Open Project/Library dialog should open. B. Locate project Indexing. The project Indexing is provided on a supplemental disk. If it is not listed on the dialog, click the Browse button on the dialog to view the projects located in the S7Proj folder. C. Double-click the Indexing icon to open the project. D. Select Expand All from View menu to expand the project s contents. The option is Expand All if using STEP 7 Version 5.2 or Show All Levels if using STEP 7 Version Perform the following substeps to download the PLC project named Indexing to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 10. Press the Output Power pushbutton to enable the PLC s outputs and home the station. 48

49 11. Perform the following substeps to adjust the sensitivity of a capacitive sensor. A. Locate the two capacitive sensors on the 87-MS3 Indexing station. The two capacitive sensors are located at positions 1 and 3, as shown in figure 44. The sensors are used to detect the presence of a part in the rotary table fixture. If a valve body is located on a fixture above the capacitive sensor, the sensor outputs a signal to the PLC. POSITION 3 POSITION 1 Figure 44. Capacitive Sensor Locations 49

50 B. Place a metallic valve body in the fixture at position 1. C. Turn the sensitivity adjustment screw, shown in figure 45, CCW to decrease the sensitivity until the metallic valve body is no longer detected. The sensor s LED indicator will turn off when the valve body is no longer detected. ADJUSTMENT SCREW INDICATOR LIGHT Function 45. Sensitivity Adjustment Screw D. Turn the adjustment screw CW until the target is just detected (LED indicator turns on). E. Replace the metallic valve body with an acrylic valve body. The acrylic valve body should not be detected with the current setting. F. Turn the adjustment screw CW until the valve body is just detected. G. Monitor the sensor s LED indicator while removing and replacing the valve body several times. H. Verify that the sensor turns on and off as the valve body is removed and replaced. I. Replace the acrylic valve body with a metallic valve body. J. Monitor the sensor s LED indicator while removing and replacing the valve body several times. The indicator light should be on when a part is sensed and off when no part is sensed. 50

51 Verify that the sensor turns on and off as the valve body is removed and replaced. If the sensor remains on when the part is removed, the sensitivity is too high. The sensor may be detecting the metallic portion of the rotary table. Repeat substeps E through J to recalibrate the sensor for the metallic valve body. If the sensor does not turn on consistently, the sensitivity is not high enough. Turn the adjustment screw 1/4 turn CW and repeat substeps I through J to verify the sensor s operation. K. Repeat substeps B though J with the capacitive sensor at position Perform the following substeps to test the operation of the capacitive sensors with the station in automatic mode. A. Place a metallic valve body on the rotary table fixture in the initial location. B. Verify the red plastic bin is mounted at the end of the parts transfer module to catch the valve body as it is pushed off. C. Place the Mode Selector switch in the Reset position. The station s actuators should home. D. Place the Mode Selector switch in the Auto position. E. Momentarily press the Start button. The station should begin to perform its sequence. F. Verify that the valve body is detected and that the station performs its sequence correctly. If not, repeat Step 11 to calibrate the sensor s sensitivity. G. Press the Stop button. H. Place an acrylic valve body in the same location as in substep A. I. Momentarily press the Start button. The station should begin to perform its sequence. J. Verify that the valve body is detected and that the station performs its sequence correctly. If not, repeat Step 11 to calibrate the sensor s sensitivity. 13. Perform the following substeps to power down the station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the Main Power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 51

52 SEGMENT 2 SELF REVIEW 1. Fiber optic sensors require an to increase the signal and output a larger signal. 2. Fiber optic sensors have two types of adjustments: and physical location. 3. A potentiometer is used to adjust the of a fiber optic sensor. 4. A capacitive sensor creates an field to sense when a part comes into range. 5. It is easier for a capacitive sensor to detect objects. 6. Capacitive proximity can be programmed to see through the wall of a and detect the material on the other side. 52

53 SEGMENT 3 STEPPER MOTOR PROGRAMMING OBJECTIVE 5 DESCRIBE HOW TO PROGRAM A STEPPER MOTOR CONTROLLER Stepper motor controllers are programmed by the user to provide the positioning and speed required by the application. The controllers accept inputs from digital sources such as standard PLC outputs, switches, and sensors (limit switches, proximity sensors) or from analog sources such as temperature or pressure sensors. Events can then be controlled based on the input. INTEGRATED CONTROLLER STEPPER MOTOR Figure 46. Stepper Motor with Integrated Controller 53

54 PC programming software is often used to develop a program for the controller. The software typically includes the following features: Operational Modes - Most programming software provides two modes of operation: programming and immediate. Programming mode is used when the commands and processes are run directly from a program in the stepper motor s controller. This mode is used for program input as well. Immediate mode is used to issue commands directly to the stepper motor controller from the PC. These commands are executed immediately. Motion Instructions - These include motion, program, I/O, and system instructions. The motion instructions control the velocity and position data and result in movement of the motor. An example would be MA 2000, where the motor will move to an absolute position of Program instructions - Program instructions allow program manipulation such as branching. An example would be BR LP, I1 = 1, which branches to a program labeled LP if input 1 is true. I/O Instructions - An I/O instruction changes the parameters or state of an input or output. An example would be PR I1, which reads the state of input 1. System Instructions - System instructions can only be used in what is called immediate mode to perform a system operation, such as a program execution or list the contents of program memory. An example would be EX K1, which will execute a program labeled K1. Variables - Most programming software includes both factory-defined and user-defined variables. The factory-defined variables cannot be deleted, but the read/writable ones can have their values altered to affect the events inside or outside of a program. User-defined variables can store and retrieve data and perform math functions. Flags - Flags show the status of an event or condition. Some flags are read/ writable so the user can set a condition or mode of operation. Keywords - Keywords are used with certain instructions to indicate or control variables and flags. An example would be PR UV, which would print the state of all the user defined variables to the screen. Math Functions - Simple math functions such as addition, subtraction, multiplication, and division as well as comparison instructions allow the programmer to perform calculations based on the values of user-defined variables. An example would be K2 = P + R2, where the user-defined variable K2 is assigned the value of P (position counter) plus the value of R2 (user register 2). 54

55 As with any other programming software, the format and syntax are specific. Specific commands may be needed at the beginning and end of each program. An example would be PG 10 and PG. PG 10 in the beginning of the program specifies at what program address to enter the program instructions in the program space, while PG at the end of the program exits program mode. It is also good programming practice to end the program, once its sequence is complete. An example of this would be E placed before the PG instruction. This ends the program before exiting program mode. Check the manufacturer s programming literature provided with the controller. Figure 47. Typical Program 55

56 STEPPER MOTOR PROGRAMMING The steps to program a stepper motor are: Step 1: Connect a PC to the stepper motor controller - The stepper motor controller typically communicates with the host PC using RS-422/485 protocol. One end of the cable has either a serial or USB connection that plugs right into the back of the PC and the other end has a connector (often 10-pin) that plugs into the motor controller. Each type of cable incorporates a converter (RS-232 to RS-485 or USB to RS-485) that allows the PC to communicate with the stepper motor. USB PORT Figure 48. Connect a PC to the Stepper Motor Controller 56

57 Step 2: Program the stepper motor - Open the programming software and enter the stepper motor program into the program editor. Once the program is typed into the editor, it is saved and then downloaded to the motor controller. After the download is complete, save the program to the controller s EEProm so it is not deleted when power is removed. Figure 49. Stepper Motor Software Step 3: Test the program - The last step is to test the program to verify that it functions as desired. The first test should be simulating the PLC outputs that signal the stepper motor to move. If the stepper motor functions as desired, then the whole station can be tested to further verify the function of the program. 57

58 SKILL 4 PROGRAM A STEPPER MOTOR CONTROLLER Procedure Overview In this procedure, you will open and view the stepper motor program and perform some online programming on the 87-MS3 Indexing station. This will familiarize you with programming of the stepper motor controller. 1. Locate the 87-MS3 Indexing station. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 50. Mechatronics Safety Check 4. Connect an air supply line to the station s air manifold quick connect. 5. Plug the station s power cable into a wall outlet. 6. Perform the following substeps to power up the station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on the air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. 58

59 7. Perform the following substeps to connect the stepper motor controller to the PC. A. Obtain the stepper motor programming cable from your instructor. B. Connect the USB connector to a spare USB port on the PC. C. Connect the 10-pin connector to the port on the stepper motor controller. The connection should appear as shown in figure 51. USB PORTS CONNECTED TO USB PORT STEPPER MOTOR PROGRAMMING CABLE 10-PIN CONNECTOR CONNECTED TO STEPPER MOTOR Figure 51. PC to Stepper Motor Connection 8. Turn the station s Main Power switch to the On position. 9. Press the Output Power pushbutton to enable the PLC s outputs. 10. Verify that all valve bodies have been removed from the indexing table. 59

60 CONNECT COMM PORT ICON 11. Perform the following substeps to open the Motion Control programming software. A. Power up the PC and monitor. B. Click on the IMS Terminal icon. C. Click on the Connect Comm Port icon, which appears as a telephone with a receiver above it, shown in figure 53. This connects the terminal window to the stepper motor. D. Click on the menu item View. E. Click on New Edit Window. A dialog box will pop up requesting a new file name. F. Type in your name followed by.mxt. This assigns your name.mxt as the file name. The.mxt extension designates the program for the MDrive motion controller. G. Click OK. Notice there are two open windows shown in figure 52. The window on the left is called the Program Editor window. This is the text editor where you can edit programs. The window on the right is called the IMS Terminal Window. This is where you can view the terminal communications. Your screen should appear similar to figure 52. Figure 52. Motion Control Programming Software 60

61 12. Perform the following substeps to upload the program from the stepper motor. This will allow you to view the program on the PC monitor. A. Click the menu item Transfer>Upload. The Upload dialog box will open. B. Select the Destination Type>Edit Window option. C. Click Upload. This will transfer the program from the motion controller. D. You can now view the program on the Edit window. Figure 53. MDrive Program 61

62 13. Perform the following substeps to move the stepper motor using the Immediate operation mode. A. Click on the View menu item. B. Click on the Terminal Window. C. Type MR and press Enter. This instructs the stepper motor to move (MR = Move Relative) 51,200 micro-steps, which should be about one revolution in approximately seconds. D. Type SL and press Enter. This instructs the stepper motor to run at a constant speed of approximately two revolutions per second. E. Type SL 0 and press Enter. The motor should decelerate to a full stop. Figure 54. Operating in Immediate Mode 14. Perform the following substeps to power down the station. A. Close both the Edit and Terminal windows on the monitor. B. Turn the Main Power switch Off. C. Disconnect the programming cable from both the motor controller and the pc. D. Turn off the PC and monitor. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 62

63 OBJECTIVE 6 DESCRIBE HOW TO ADJUST A HOMING SENSOR A rotary table s homing sensor is often an inductive sensor because the table is metal and it is a low cost proximity sensor. One way to trigger the sensor is to use a series of holes that are located at positions in the surface of the rotary table that correspond to the fixtures. The holes define the home positions of the table. When the rotary table is homed, it can home to any of the holes that are detected by the homing sensor. This places all of the table s fixtures in the proper position to process parts. HOMING SENSOR POSITION 3 HOLES FOR HOMING SENSOR POSITION 1 Figure 55. Rotary Table 63

64 The stepper motor program homes the rotary table each time power is applied to the stepper motor. This is the very first command in the stepper motor controller s programming and is initiated on every power up. The inductive homing sensor s output usually wires to both the PLC and the stepper motor. During the homing sequence, as the table rotates and a hole passes over the homing sensor, the sensor de-energizes. This indicates to the PLC and stepper motor that the table is near the home position because each hole is in line with the work position. When the stepper motor sees the homing sensor go off, it stops and reverses the direction of the rotary table s rotation and slowly moves the table back to where the sensor turns on again. Part of the sensor is typically visible through the hole used in the homing sequence. HOMING SENSOR TABLE ROTATES UNTIL HOMING SENSOR PASSES UNDER HOLE AND SENSOR GOES OFF TABLE ROTATES SLOWLY BACK UNTIL SENSOR GOES ON AGAIN Figure 56. Sensor Operation 64

65 Homing Sensor Adjustment Homing sensors may need to be adjusted after maintenance or repairs on the rotary table station. The steps to adjust the physical location of an inductive homing sensor are: Step 1: Loosen the locknuts on the sensor - Locate the homing sensor on its mounting beneath the indexing table. Loosen the top or bottom locknut so the sensor can move freely. INDEX TABLE LOCKNUTS BULKHEAD Figure 57. Loosen the Locknuts SENSOR 65

66 Step 2: Relocate the sensor - Relocate the sensor the desired location. That may be left/right or up/down of the current location. This involves sliding the sensor left or right or turning the locknuts (CW or CCW) to move the sensor closer or further from the indexing table. MOVE LEFT OR RIGHT MOVE UP OR DOWN Figure 58. Adjust Sensor Location 66

67 Step 3: Tighten the locknuts on the sensor - Retighten the top or bottom locknut on the sensor to secure it in place. Step 5: Test the homing operation - Operate the homing sequence on the indexing table. Verify that the indexing table stops with a work position directly in front of the work areas. WORK AREA HOMING SENSOR WORK POSITION Figure 59. Test the Homing Operation 67

68 SKILL 5 ADJUST A HOMING SENSOR Procedure Overview In this procedure, you will manually adjust the homing sensor on the 87-MS3 Indexing station. This will familiarize you with the station and with manually adjusting a homing sensor. 1. Locate the 87-MS3 Indexing station. 2. Verify that this station has been separated from any other stations. If it has not, then separate it from the other stations. If it has, then proceed to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 60. Mechatronics Safety Check 4. Connect an air supply line to the station s air manifold quick connect. 5. Plug the station s power cable into a wall outlet. 6. Perform the following substeps to power up the station. A. Place the Mode Selector switch in the Manual position. B. Remove the lockout/tagout device from the electrical power source. C. Remove the lockout/tagout device from the pneumatic power source. D. Turn on the air to the station by shifting the lever on the lockout valve. E. Set the station s air supply regulator to 50 psi/345 kpa. F. Turn the station s Main Power Switch to the On position. 7. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 68

69 8. Perform the following substeps to open project Indexing. A. Click the Open Project/Library button. The Open Project/Library dialog should open. B. Locate project Indexing. The project Indexing is provided on a supplemental disk. If it is not listed on the dialog, click the Browse button on the dialog to view the projects located in the S7Proj folder. C. Double-click the Indexing icon to open the project. D. Select Expand All from View menu to expand the project s contents. The option is Expand All if using STEP 7 Version 5.2 or Show All Levels if using STEP 7 Version Perform the following substeps to download the PLC project named Indexing to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 10. Press the Output Power pushbutton to enable the PLC s outputs. 11. Perform the following substeps to home the station. A. Turn the Mode Selector switch to Reset. This will home all of the actuators. B. Turn the Mode Selector switch back to Manual. 69

70 12. Perform the following substeps to adjust the homing sensor s horizontal position. A. Locate the homing sensor on the 87-MS3 Indexing station. The homing sensor is an inductive sensor located toward the rear of the rotary table in front of the gripper as shown in figure 61. HOMING SENSOR Figure 61. Homing Sensor Position 70

71 The table should currently be in the home position, which is directly in front of the gripper. Notice the physical layout of the rotary table. There are 8 different fixtures spaced 45 apart around the table. Each fixture can hold a valve body that is being processed. A hole is located in front of each of the fixtures. The homing sensor detects the hole when it passes over the sensor. The sensor s output indicates to the PLC and the stepper motor that the rotary table is in the proper position to process a part when the sensor is activated. The sensor has two outputs, one N.C. and one N.O. The N.C. contacts are wired as an input to the PLC. The N.O. contacts are wired as an input to the stepper motor. The sensor has a yellow LED at the rear of the unit that indicates its status. The LED should be on since the station was homed in a previous step. LED Figure 62. Homing Sensor B. Turn the station s Main Power switch to the Off position. C. Turn the station s Main Power switch to the On position. This will cause the table to home itself again. 71

72 D. Press the Output Power pushbutton to enable the PLC s outputs. The rotary table is programmed to home when the output power is applied to the station. This provides the stepper motor with an initial starting location. You should notice that the table rotates slowly CCW until the sensor s LED turns off. It then should rotate CW slightly until the LED turns back on. When homed, the fixture should be directly in front of the gripper, as shown in figure 63. The homing sensor should be offset slightly from the hole, as shown in figure 63. HOMING SENSOR GRIPPER Figure 63. Rotary Table in Home Position 72

73 E. Turn the station s Main Power Switch to the Off position. F. Mark the location of the sensor on its mount so that it can be returned to its original position. You can use tape or a grease pencil for this. G. Use a 11/16 in. open end wrench to loosen the top locking nut, shown in figure 64, that secures the sensor to the bracket. Notice the cutout that allows the sensor to be positioned horizontally. TOP LOCKNUT CUTOUT Figure 64. Sensor Mount H. Slide the sensor approximately 1/2 inch left or right from its current location. I. Tighten the locking nut. J. Turn the station s Main Power Switch to the On position. 73

74 K. Press the Output Power pushbutton to enable the PLC s outputs and home the rotary table. You should notice that the table attempts to find the home position. Depending on your adjustment, the sensor may either not actuate at all, or may actuate and cause the table to home to the wrong position. If it homes in the wrong position, the fixture will be offset from the gripper as shown in figure 65. HOME POSITION MISADJUSTED Figure 65. Gripper and Fixture with Home Position Misadjusted L. Turn the station s Main Power switch to the Off position. M. Move the sensor back to its original location, which you previously marked, and tighten the locking nut. N. Turn the station s Main Power Switch to the On position. O. Press the Output Power pushbutton to enable the PLC s outputs and home the rotary table. The rotary table should home correctly. 13. Perform the following substeps to adjust the homing sensor s vertical position. A. Turn the station s Main Power Switch to the Off position. B. Loosen the top locknut five turns. C. Tighten the bottom locking nut so that the sensor is in the original position, but farther away from the rotary table. D. Turn the station s Main Power Switch to the On position. E. Press the Output Power pushbutton to enable the PLC s outputs and home the rotary table. The table should home, but it should be slightly off. Since the sensor is further away from the table, a larger surface area of metal must be in front of it before it turns on. F. Turn the station s Main Power Switch to the Off position. G. Loosen the bottom locknut five turns. 74

75 H. Tighten the top locknut to bring the sensor closer to the table. I. Turn the station s Main Power Switch to the On position J. Press the Output Power pushbutton to enable the PLC s outputs and home the rotary table. You should find that the station homes correctly. If not, continue to adjust the sensor until the table homes correctly. 14. Perform the following substeps to power down the station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the Main Power switch Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 75

76 SEGMENT 3 SELF REVIEW 1. Stepper motors are programmed by the user to provide the and speed required by the application. 2. Motion instructions control the velocity and data and result in movement of the motor. 3. System program instructions can only be used in mode to perform a system operation. 4. A homing sensor on a rotary table is usually an sensor. 5. The stepper motor homes the rotary table every time is applied to the stepper motor. 6. The homing sensor s output is usually wired to both the stepper motor and the. 76

77 SEGMENT 4 MODULE SEQUENCING OBJECTIVE 7 DESCRIBE A SEQUENCE OF OPERATION OF A PART TRANSFER MODULE A typical part transfer module, shown in figure 66, includes a single-solenoid directional control valve and a double-acting cylinder that is used to redirect parts from one machine or station to another. The double acting cylinder is often equipped with sensors to detect when the transfer cylinder is in its fully extended and fully retracted positions. In this example, two magnetic reed (MR) switches detect the cylinder s position. TRANSFER PART PARTS BIN MAGNETIC REED SWITCHES Figure 66. Transfer Module Construction 77

78 Transfer modules are typically PLC controlled. The sequence will be similar to that shown in the table below. TRANSFER MODULE SEQUENCE Step INPUT OUTPUT 1 Receive Start Input (S1 on) Transfer Cylinder Extends (SOL1 on) 2 Transfer Cylinder Fully Extended Transfer Cylinder Retracts (MR2 on) 3 Transfer Cylinder Fully Retracted (MR1 on) Cycle Ends Figure 67. Transfer Module Sequence of Operation Initial Condition The transfer module must be in some pre-determined state before any sequence may take place. Many times this will be a state in which the feed cylinder is retracted (MR1 actuated). In some cases, there may be an interlock, indicating that motion at the source and/or destination station has stopped and it is now safe to transfer. One example would be that the source station s transfer table has stopped moving. If these initial conditions are not satisfied, the transfer module will not operate and the PLC controlling the module may even provide an alarm light or message to the operator, indicating that operator intervention is necessary. RETRACTED MR1 ON FROM SOURCE SOL1 TRANSFER RETRACTED MR1 EXTENDED MR2 Figure 68. Initial Condition 78

79 Step 1: Receive Start Input, Transfer Cylinder Extend In this step, the PLC controlling the transfer module receives an input to start the transfer sequence. The input may be from another workstation, an input detecting that a part is present and ready to be transferred, or it may be from an operator. After receiving the input signal, the PLC energizes solenoid valve SOL1 and the transfer cylinder extends, redirecting the part to the next station. TRANSFER BEGINS TO EXTEND PART FROM SOURCE SOL1 TRANSFER RETRACTED MR1 EXTENDED MR2 Figure 69. Step 1: Receive Start Input, Transfer Cylinder Extend 79

80 Step 2: Transfer Cylinder Fully Extended, Transfer Cylinder Retract Once the transfer cylinder is fully extended (MR2 on) and the part redirected, SOL1 is de-energized by the controller and the transfer cylinder retracts. MR2 ON PART IN BIN FROM SOURCE SOL1 TRANSFER RETRACTED MR1 EXTENDED MR2 Figure 70. Step 2: Transfer Cylinder Fully Extended, Transfer Cylinder Retracts 80

81 Step 3: Transfer Cylinder Fully Retracted, Cycle Ends The transfer cylinder continues to retract until it is in its fully retracted position (MR1 actuated). The transfer module s cylinder will remain retracted until the next start signal. MR1 ON MR2 OFF TRANSFER RETRACTED FROM SOURCE SOL1 TRANSFER RETRACTED MR1 EXTENDED MR2 Figure 71. Step 3: Transfer Cylinder Fully Retracted, Cycle Ends The sequence just described is summarized by sequence diagram in figure 72. PART TRANSFER MODULE SEQUENCE OF OPERATION INPUTS OUTPUTS Step Input Action Output Action Start PB Stop PB MR1 MR2 SOL1 0 Start Condition Receive Start Input Extend Transfer Cylinder 1/0 1 2 Transfer Cylinder Extended Retract Transfer Cylinder Transfer Cylinder Retracted Cycle Ends 1 0 End Condition Figure 72. Sequence Diagram 81

82 SKILL 6 DESIGN A PLC PROGRAM THAT SEQUENCES A PART TRANSFER MODULE Procedure Overview In this procedure, you will design and test a PLC program that uses a single-solenoid DCV to control the powered parts feeder on the 87-MS3 Indexing station. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start pushbutton (PB1) causes the transfer module s transfer cylinder to extend. 2) Once the cylinder has fully extended, activating MR2, it will retract. 3) When the cylinder has fully retracted, activating MR1, the process will stop. Special Conditions: Pressing the Stop pushbutton at any time will cause the cylinder to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence. The Start pushbutton lamp will be off when ready (motor ready signal on) and turn on solid as the station is operating. An interlock (Stepper Motor Ready) is used to keep the transfer cylinder from extending unless the stepper motor is stationary. INPUTS PB MR1 MR2 START INPUT I0.0 TRANSFER RETRACTED I1.2 TRANSFER EXTENDED I1.3 I/O DIAGRAM Q4.0 OUTPUTS ACTIVE LAMP TRANSFER EXTEND (SOL1) Q4.5 SM1 STEPPER MOTOR READY I2.6 Figure 73. I/O Diagram 82

83 FROM SOURCE SOL1 TRANSFER RETRACTED MR1 EXTENDED MR2 Figure 74. Power Diagram PART TRANSFER MODULE SEQUENCE OF OPERATION INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input Extend Transfer Cylinder 1/0 1 2 Transfer Cylinder Extended Retract Transfer Cylinder Transfer Cylinder Retracted Cycle Ends 1 0 End Condition Figure 75. Sequence Diagram Start PB (I0.0) Stop PB (I0.1) 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. MR1 (I1.2) MR2 (I1.3) SM1 (I2.6) SOL1 (Q4.5) 83

84 3. Perform the following substeps to create a project. A. Create a Project named L5S6XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 2 into Organizational Block OB1. E. ave OB1. 4. If the 87-MS3 Indexing station is connected to another station, separate the stations. If the 87-MS3 Indexing station is already disconnected, continue to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 76. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Perform the following substeps to power up the 87-MS3 Indexing Station. A. Remove the lockout/tagout device from the electrical power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Turn the station s Main Power Switch to the On position. 84

85 9. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 10. Go online with the processor and monitor the OB1 Block. 11. Place a valve body on the transfer module, as shown in figure 77. Figure 77. Valve Body Placement 12. Press the Output Power pushbutton to enable the PLC s outputs. 13. Place a parts bin at the Transfer Module s destination to capture the parts as they are transferred from the Indexing Table. 85

86 14. Perform the following substeps to test the PLC program. At this time, the Start pushbutton lamp should be off. A. Press the Start pushbutton momentarily. The transfer cylinder should extend completely, transferring a part from the indexing table into the parts bin. The start pushbutton lamp should turn on and remain on as this occurs. B. Place another valve body on the transfer module. C. Press the Start pushbutton and then quickly press the Stop pushbutton before the cylinder has become fully extended. The transfer cylinder should extend completely, transferring another part and then halt in the extended position. D. Press the Start pushbutton again. The transfer cylinder should continue its current sequence, retract and stop. 15. Perform the following substeps to shut down the 87-MS3 Indexing station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS3 s main power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 86

87 OBJECTIVE 8 DESCRIBE A SEQUENCE OF OPERATION OF A STEPPER MOTOR INDEX TABLE Stepper motor indexing tables are normally set up to accommodate a number of workstations located around the perimeter of the table. Workstations are usually arranged at equal angular intervals around the indexing table (e.g. every 22.5, 45, or 90 ) so that as the table is indexed, all parts are transferred to the next workstation. Typically two stations are dedicated transfer stations, one to receive incoming parts, and one to transfer outbound parts to the next station. As parts or assemblies are indexed from one workstation to the next, each workstation is given the opportunity to perform work on the part INCOMING OUTGOING Figure 78. Typical Stepper Motor Indexing Application 87

88 A typical stepper motor indexing table will have one input from the stepper motor to the PLC indicating when the motor is stationary (Stepper Motor Ready, SM1), and a sensor input to the PLC indicating when a part is present at the inbound transfer point (CS2). The PLC will then use a couple of outputs to energize the stepper motor s user-defined inputs (Stepper Motor Go 45 and Stepper Motor Go 90) to index the table a predetermined amount (45, 90, or a combination of these). HOMING SENSOR INBOUND TRANSFER POINT (CS2) 0 INDEX TABLE 180 IN OUT PLC SM GO 45 SM MOTOR GO 90 STEPPER MOTOR WITH INTEGRATED CONTROLLER STEPPER MOTOR READY (SM1) Figure 79. Stepper Motor and Sensor Positions The sequence of a typical stepper motor index table is similar to that shown in the table of figure 80. STEPPER MOTOR INDEX TABLE SEQUENCE STEP INPUT OUTPUT 1 Receive Start input/part present sensor activated (S1 on, CS2 on) 2 Stepper Motor ready (completes index, SM1 on) Figure 80. Stepper Motor Index Table Sequence Index Stepper motor 45 degrees (SM Go 45 on) Cycle Ends 88

89 Initial Condition The stepper motor index table must be in some pre-determined state before any sequence may take place. In this case, the motor must be in its homed position and motionless and a part must be detected (CS2 on) in order for any sequence to start. The homing procedure is often obtained by programming one of the stepper motor s discrete I/O points as a homing input and tying the input to the master control relay so that when the PLC s outputs are energized, the indexing table homes automatically. To detect when the motor is motionless, one of the other stepper motor s discrete outputs is programmed as a general purpose output. Within the stepper motor program, this output is programmed to turn on when the motor is programmed to remain stationary. The output is then used as an input to the PLC (Stepper Motor Ready, SM1) to indicate the stepper motor is motionless. INDEX TABLE HOMED HOMING SENSOR ACTIVE STEPPER MOTOR READY CAPACITIVE PARTS PRESENT SENSOR (CS2 ON) STEPPER INDUCTIVE HOMING SENSOR (IND1 ON) Figure 81. Initial Condition 89

90 Step 1: Start Input Received, Index Stepper Motor 45 Degrees In this step, the PLC receives a start input signal from another workstation or an operator. Assuming that the stepper motor has been homed and the Part Present sensor sees a part (CS2 on), the input signal causes the PLC to energize the Stepper Motor Go 45 (SM Go 45) output. This energizes the stepper motor s user-defined input. The stepper motor controller senses the input and turns the motor on so that it turns 45 as dictated by its program. TABLE BEGINS TO ROTATE 45 CS2 ON MOTOR MOTOR ON S1 ON SM GO 45 STEPPER CS2 ON Figure 82. Step 1: Start Input Received, Index Stepper Motor 45 Degrees 90

91 Step 2: Stepper Motor Ready, Cycle Ends Once the stepper motor has moved its 45 and come to a complete stop, it energizes its user-defined, general-purpose output, which signals to the PLC that the motor is stationary (Stepper Motor Ready). The indexing table is now in its initial condition. The cycle will repeat the next time that a part is transferred onto the table and the start input is received again. PART IND1 ON CS2 OFF MOTOR OFF MOTOR OFF IND1 ON STEPPER CS2 OFF Figure 83. Step 2: Stepper Motor Ready, Cycle Ends 91

92 This stepper motor indexing sequence just described is summarized in the sequence diagram in figure 84. STEPPER MOTOR INDEX SEQUENCE DIAGRAM INPUTS OUTPUTS Input Action Output Action Start PB Stop PB IND1 Motor Ready CS2 Motor go 45 Start Condition Receive Start Input Table indexes 45 1/0 1 Stepper Motor Ready Cycle stop 0 0 End Condition Figure 84. Sequence Diagram 92

93 SKILL 7 DESIGN A PLC PROGRAM THAT SEQUENCES A STEPPER MOTOR INDEX TABLE Procedure Overview In this procedure, you will design and test a PLC program that uses a capacitive sensor and stepper motor controller to control the operation of an indexing table. 1. Design a ladder logic routine given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence 1) Pressing the Start pushbutton enables the PLC program, which indexes the table 45 (Stepper Motor Go 45). 2) Once the indexing table movement stops, the stepper motor controller energizes its motor ready output (Stepper Motor Ready). The cycle will repeat the next time a part is transferred onto the indexing station and the start pushbutton is pressed. Special Conditions The sequence cannot be started unless the stepper motor is homed (IND1 on) and stationary (motor ready signal on) and the part present sensor CS2 is on. The Start pushbutton lamp will turn off when ready (motor ready signal on) and turn solid as the station is operating. 93

94 INPUTS I/O DIAGRAM PB START INPUT I0.0 Q4.0 OUTPUTS ACTIVE LAMP IND1 HOME POSITION 12.5 Q5.2 MOTOR GO 45 SM1 STEPPER MOTOR READY I2.6 CS2 PART PRESENT I2.7 Figure 85. I/O Diagram STEPPER INDUCTIVE SENSOR IND1 CAPACITIVE SENSOR CS2 Figure 86. Power Diagram 94

95 STEPPER MOTOR INDEX SEQUENCE DIAGRAM INPUTS OUTPUTS Input Action Output Action Start Condition Receive Start Input Table indexes 45 1/0 1 Stepper Motor Ready Cycle stop 0 0 End Condition Figure 87. Sequence Diagram Start PB (I0.0) Stop PB (I0.1) 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L5S7XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. If the 87-MS3 Indexing station is connected to another 87-MS station, separate the stations. If the 87-MS3 Indexing station is already disconnected, continue to Step 5. IND1 (I2.5) Motor Ready (I2.6) CS2 (I2.7) Motor go 45 (Q5.2) 95

96 5. Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 88. Mechatronics Safety Check 6. Connect an air supply to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Perform the following substeps to power up the 87-MS3 Indexing station A. Remove the lockout/tagout device from the electrical power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Turn the station s Main Power Switch to the On position. 9. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 10. Go online with the processor and monitor the OB1 Block. 11. Press the Output Power pushbutton to enable the PLC s outputs. 96

97 12. Perform the following substeps to test the operation of the program. A. Place a valve body at the indexing table s initial location as shown in figure 89. This should have no effect on the indexing station, as the Start pushbutton has not yet been pressed. Figure 89. Valve Body Placement B. Press and release the Start pushbutton. The Start pushbutton s active indicator should turn on, indicating that the stepper motor indexing table program is running and the indexing table should move Click the Monitor button to go offline from the processor. 14. Use the PLC programming software to place the PLC into STOP mode. 15. Print out a copy of the ladder logic program and place it in your portfolio. It will be used in your assessment. 16. Perform the following substeps to shut down the 87-MS3 Indexing. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS3 s Main Power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 97

98 OBJECTIVE 9 DESCRIBE A SEQUENCE OF OPERATION OF A PARTS ORIENTATION MODULE Industrial applications often use two-axis manipulators, like the one shown in figure 90, for parts orientation. In this application, the manipulator grasps a part (or assembly), lifts, rotates, and then replaces the part so that it is correctly oriented for the next workstation in the process. The PLC uses three two-solenoid directional control valves to actuate the manipulator s gripper (release-sol2a and grip-sol2b), y-axis (extend-sol4a and retract-sol4b), and rotational motion (CW-SOL3A and CCW-3B). Four magnetic reed switches are used to detect when the manipulator s y-axis cylinder is in its fully extended (GMR4) and fully retracted (GMR3) positions, as well as when the rotational axis is rotated clockwise (MR5) or counterclockwise (MR6). The module also uses a capacitive part present sensor (CS1). ROTATION GRIPPER MR6 MR5 Y-AXIS GMR4 GMR3 CS1 Figure 90. Parts Orientation Module Construction 98

99 A typical sequence is shown in the table below. PARTS ORIENTATION MODULE SEQUENCE STEP INPUT OUTPUT 1 Receive Start Input (S1 on, CS1 on) Retract Y-Axis (SOL4B on) 2 Y-Axis Retracted (GMR3 on) Close Gripper (SOL2B on, Grip timer starts) 3 Gipper Closed (Timer done) Extend Y-Axis (SOL4A on) 4 Y-Axis Extended (GMR4 on) Rotate Gripper (SOL3A on) 5 Gripper Rotated (MR6 on) Retract Y-Axis (SOL4B on) 6 Y-Axis Retracted (GMR3 on, CS1 on) Open Gripper (SOL2A on, Grip Timer starts) 7 Gripper Opened (Timer done) Extend Y-Axis (SOL4A on) 8 Y-Axis Extended (GMR4 on) Cycle Ends Figure 91. Indexing Station Sequence of Operation 99

100 Initial Condition The parts orientation module must be in a position that is clear of the indexing table and in a predetermined position before any sequence may take place. Many times this will be a state in which the y-axis is extended (GMR4 actuated) the gripper is open and rotated fully clockwise (MR5 on), which is the home position, and a part in position (CS1 on). GRIPPER OPEN MR5 ON Y-AXIS EXTENDED GMR4 ON CS1 ON FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B SOL3A GMR4 EXTENDED ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 92. Initial Condition 100

101 Step 1: Receive Start Input, Retract Y-Axis Cylinder In this step, the PLC controlling the transfer module receives an input indicating that the part or assembly requires orientation. The input is often a signal from a fiber optic sensor or vision system of some type. These types of sensors are used to check a part for a particular attribute. If the attribute is detected, the part is assumed to be good and will not be manipulated. If, however, the attribute is not detected, the input is used to start the orientation module sequence. In this case, the y-axis cylinder retracts (SOL4B on). Y-AXIS BEGINS TO RETRACT FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 93. Step 1: Receive Start Input, Retract Y-Axis Cylinder 101

102 Step 2: Y-Axis Retracted, Close Gripper Once the manipulator s y-axis is retracted (GMR3 on), the gripper closes (SOL2B on) and the valve body is grasped. If the gripper has no sensors to detect gripper status (open/closed), a timer begins timing to provide the time delay necessary to ensure that the DCV has shifted and the gripper fingers have closed. PART Y-AXIS RETRACTED GMR4 OFF GMR3 ON FROM SOURCE GRIPPER BEGINS TO CLOSE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 94. Step 2: Y-Axis Retracted, Gripper Closes 102

103 Step 3: Gripper Closed, Extend Y-Axis After the gripper is closed and the timer times out, the manipulator s y-axis extends (SOL4A on SOL4B off) and lifts the part from the table. Y-AXIS BEGINS TO EXTEND FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 95. Step 3: Gripper Closed, Y-Axis Extends 103

104 Step 4: Y-Axis Extended, Rotate Gripper Once the y-axis has extended (GMR4 on) and the manipulator and part are both clear of the indexing table (CS1 off), the PLC turns on (SOL3A) to rotate the part. GRIPPER BEGINS TO ROTATE Y-AXIS EXTENDED GMR4 ON GMR3 OFF CS1 OFF FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 96. Step 4: Y-Axis Extended, Gripper Rotates 104

105 Step 5: Gripper Rotated, Retract Y-Axis As the gripper rotates, it actuates the magnetic reed switch (MR6). This causes the Indexing station s y-axis to retract (SOL4A off and SOL4B on) and the flipped part starts back towards the stepper motor indexing table. MR5 OFF MR6 ON Y-AXIS BEGINS TO RETRACT FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATION SOL2A GRIPPER CLOSED SOL2B OPEN Figure 97. Step 5: Gripper Rotated, Y-Axis Retracts 105

106 Step 6: Y-Axis Retracted, Open Gripper As the y-axis retracts fully (GMR3 on), it sets the part back onto the indexing table (CS1 on) and opens the manipulator s gripper (SOL2B off and SOL2A on). A timer is started to allow the gripper time to open fully. The newly oriented part is released back onto the table. GRIPPER BEGINS TO OPEN Y-AXIS RETRACTED GMR4 OFF GMR3 ON CS1 ON FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B GMR4 EXTENDED SOL3A ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 98. Step 6: Y-Axis Retracted, Gripper Opens 106

107 Step 7: Gripper Opened, Extend Y-Axis Once the gripper is opened, indicated by the completion of the timer, the PLC extends the manipulator s y-axis (SOL4A on and SOL4B off). This moves the manipulator clear of the table and any parts on it so that it may index without colliding into the manipulator. PART RELEASED TO TABLE Y-AXIS BEGINS TO EXTEND FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B SOL3A GMR4 EXTENDED ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 99. Step 7: Gripper Opened, Y-Axis Extends 107

108 Step 8: Y-Axis Extended, Cycle Ends Once the manipulator s y-axis is extended (GMR4 on), the parts orientation module is ready to repeat the cycle, once the part is removed and the start signal is received again. GMR4 ON GMR3 OFF Y-AXIS EXTENDED FROM SOURCE SOL4A LIFT GMR3 RETRACTED SOL4B SOL3A GMR4 EXTENDED ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 100. Step 8: Y-Axis Extended, Cycle Ends 108

109 The sequence just described is summarized by sequence diagram in figure 101. PARTS ORIENTATION MODULE SEQUENCE DIAGRAM INPUTS OUTPUTS Step Input Action Output Action Start PB Stop PB GMR3 GMR4 MR5 MR6 CS1 SOL4A SOL4B SOL2A SOL2B SOL3A SOL3B 0 Start Condition Receive Start Input Retract Y-Axis 1/0 1 2 Y-Axis Retracted Close Gripper, Start Time Delay Gripper Closed, Time Delay End Extend Y-Axis Y-Axis Extended Rotate Gripper Gripper Rotated Retract Y-Axis Y-Axis Retracted Open Gripper, Start Time Delay Gripper Opened, Time Delay End Extend Y-Axis Y-Axis Extended Cycle Ends End Condition Figure 101. Sequence Diagram 109

110 SKILL 8 DESIGN A PLC PROGRAM THAT SEQUENCES A PART ORIENTATION MODULE Procedure Overview In this procedure, you will design and test a PLC program that uses a twoaxis manipulator to correctly orient parts for the next workstation. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start pushbutton (PB1) causes the pneumatic manipulator s y-axis to retract (SOL4B on). 2) Once the y-axis is retracted (GMR3 on), the gripper closes (SOL2B on) starting a short time delay and the valve body is grasped. 3) After time delay is done, the manipulator s y-axis extends (SOL4A on and SOL4B off) and the manipulator lifts the valve body. 4) Once the y-axis has extended (GMR4 on) and the capacitive proximity sensor (CS1) is off, the PLC looks at the gripper rotation sensors (MR5 CW and MR6 CCW) to determine which sensor is on to know which direction to rotate the gripper, then the gripper rotates 180 (SOL3A or 3B). 5) After the gripper rotates 180 (MR5 or MR6 on), the y-axis retracts (SOL4A off and 4B on). 6) As the y-axis retracts fully (GMR3 on), the gripper opens (SOL2B off and SOL2A on), and CS1 turns back on. 7) After a short time delay to allow the gripper to open fully, the y-axis extends (SOL4A on). 110

111 Special Conditions: Pressing the Stop pushbutton at any time will cause the manipulator to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence from that step. The sequence cannot be started unless the stepper motor is homed and stationary (motor ready signal on) and the part present sensor at the orientation station (CS1) is on. The Start pushbutton lamp will be off when the manipulator is in its home position (y-axis extended, gripper rotated fully either direction, and gripper fingers open). INPUTS I/O DIAGRAM OUTPUTS PB START INPUT I0.0 Q4.0 ACTIVE LAMP GMR3 LIFT RETRACTED I1.4 Q4.6 LIFT EXTEND (SOL4A) GMR4 LIFT EXTENDED I1.5 Q4.7 LIFT RETRACT (SOL4B) CS1 PART PRESENT ORIENTATION MODULE I2.1 Q5.4 GRIPPER OPEN (SOL2A) MR5 MR6 SM1 ROTATION RETRACTED I2.2 ROTATION EXTENDED I2.3 STEPPER MOTOR READY I2.6 Q5.5 Q5.6 Q5.7 GRIPPER CLOSED (SOL2B) ROTATION EXTEND (SOL3A) ROTATION RETRACT (SOL3B) Figure 102. I/O Diagram 111

112 FROM SOURCE SOL4A Y-AXIS GMR3 RETRACTED SOL4B SOL3A GMR4 EXTENDED SOL3B ROTATION MR5 MR6 EXTENDED RETRACTED SOL2A GRIPPER CLOSED SOL2B OPEN Figure 103. Power Diagram PARTS ORIENTATION MODULE SEQUENCE DIAGRAM INPUTS OUTPUTS Step Input Action Output Action Start PB (I0.0) Stop PB (I0.1) GMR3 (I1.4) GMR4 (I1.5) MR5 (I2.2) MR6 (I2.3) CS1 (I2.1) SM1 (I2.6) SOL4A (Q4.6) SOL4B (Q4.7) SOL2A (Q5.4) SOL2B (Q5.5) SOL3A (Q5.6) SOL3B (Q5.7) 0 Start Condition Receive Start Input Retract Y-Axis 1/0 1 2 Y-Axis Retracted Close Gripper, Start Time Delay Gripper Closed, Time Delay End Extend Y-Axis Y-Axis Extended Rotate Gripper Gripper Rotated Retract Y-Axis Y-Axis Retracted Open Gripper, Start Time Delay Gripper Opened, Time Delay End Extend Y-Axis Y-Axis Extended Cycle Ends End Condition Figure 104. Sequence Diagram 112

113 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L5S8XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. 4. If the 87-MS3 Indexing station is connected to another station, separate the stations. If the 87-MS3 Indexing station is already disconnected, continue to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 105. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 113

114 8. Perform the following substeps to power up the 87-MS3 Indexing station. A. Remove the lockout/tagout device from the electrical power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Turn the station s Main Power Switch to the On position. 9. Press the Output Power pushbutton to enable the PLC s outputs. 10. Use the DCV s manual overrides to home the pneumatic manipulator (y-axis extended, gripper open and rotation cylinder retracted). Figure 106. DCV s Manual Overrides 11. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 114

115 12. Go online with the processor and monitor the OB1 Block. 13. Place a valve body in front of the pneumatic manipulator, as shown in figure 107. VALVE BODY Figure 107. Valve Body Replacement 14. Perform the following substeps to test the PLC program. At this time, the Start pushbutton indicator should be off indicating that the station is ready to run. A. Press the Start pushbutton momentarily. After receiving the input signal, the manipulator should perform the following sequence: Retract its y-axis towards the pickup point. Close the gripper and grasp the part. Extend the y-axis with part in gripper. Once the y-axis is extended, rotate gripper to flip the part. After the part is flipped, retract the y-axis towards the pickup point. After retracting, the manipulator should open the gripper to release part. Once part is released, extend the y-axis. The Start pushbutton indicator should be solid during this sequence. Once the sequence is complete, the indicator should turn off. B. Place another valve body on the orientation module. C. Press the Start pushbutton and then quickly press the Stop pushbutton. The manipulator should halt after its current step. 115

116 D. Press the Start pushbutton again. The manipulator should resume operation from its current step and complete its cycle. 15. Perform the following substeps to shut down the 87-MS3 Indexing station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS3 s Main Power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 116

117 SEGMENT 4 SELF REVIEW 1. Transfer modules are usually controlled by. 2. Double acting cylinders are often equipped with to detect when the cylinder is fully extended or fully retracted. 3. A typical part transfer module includes a double-acting cylinder that parts from one station to another. 4. Stepper motor indexing tables are normally set up to accommodate a number of workstations arranged at equal angular around the table. 5. A typical stepper motor indexing table will have an input from the stepper motor controller to the PLC and one from a to the PLC. 6. Industrial applications use two-axis manipulators as parts modules. 117

118 SEGMENT 5 STATION SEQUENCING OBJECTIVE 10 DESCRIBE A SEQUENCE OF OPERATION OF AN INDEXING STATION Although an indexing station consists of multiple modules that perform different tasks, one PLC program is typically used to control the operation of all of the modules. An example of an indexing station is shown in figure 108. In this application, the part starts at the initial location and then rotates to the inspection module, where its orientation is checked by a fiber optic sensor. If the part is oriented correctly, the table rotates 135, where it transfers the part by a cylinder to the next station. If the sensor detects incorrect orientation, the table rotates 45 to the orientation module, where a 2-axis pneumatic manipulator picks it up and turns it over. The table then rotates the part to the transfer module where it is transferred to the next station. FIBER OPTIC INSPECTION MODULE 2-AXIS ORIENTATION MODULE NEXT STATION INITIAL LOCATION INDEXING MODULE TRANSFER MODULE Figure 108. Orientation Processing Module 118

119 In the automatic mode, the Indexing station performs a sequence of operation every cycle under the control of a PLC. A typical sequence of operation of an Indexing station is shown in figure 109. INDEXING STATION SEQUENCE- INCORRECT PART ORIENTATION STEP INPUT OUTPUT 1 Receive Start Input/Part presen sensor activated Index Stepper motor 45 (SM Go 45 on) (S1 on, CS2 on) 2 Stepper motor ready (completes index)/ Sensor Index Stepper motor 45 (SM Go 45 on) indicates part is not oriented correctly (port not detected) (SM1 on) 3 Stepper motor ready (completes index)/part present Retract Y-axis (SOL4B on) sensor activated (SM1 on, CS1 on) 4 Y-Axis Retracted (GMR3 on) Close Gripper/Start time delay (SOL2B on, Grip timer starts) 5 Gripper closed/time delay ends (Timer done) Extend Y-axis (SOL4A on) 6 Y-Axis Extended (GMR4 on) Rotate Gripper 180 (SOL3A on) 7 Gripper Rotated 180 (MR6 on) Retract Y-Axis (SOL4B on) 8 Y-Axis Retracted (GMR3 on, CS1 on) Open Gripper/Start time delay (SOL2A on, Grip timer starts) 9 Gripper Opened/Time delay ends (Timer done) Extend Y-axis (SOL4A on) 10 Y-Axis Extended (GMR4 on) Index Stepper Motor 90 (SM Go 90 on) 11 Stepper motor ready (completes index) (SM1 on) Extend Transfer cylinder (SOL1 on) 12 Transfer cylinder extended (MR2 on) Retract Transfer Cylinder 13 Transfer cylinder retracted (MR1 on) Cycle Ends INDEXING STATION SEQUENCE- CORRECT PART ORIENTATION STEP INPUT OUTPUT 1 Receive Start Input/Part presen sensor activated (S1 on, CS2 on) Index Stepper motor 45 (SM Go 45 on) 2 Stepper motor ready (completes index)/ Sensor indicates part is oriented correctly (port detected) (SM1 on, PS1 on) Index Stepper motor 135 (SM Go 45 on, SM Go 90 on) 3 Stepper motor ready (completes index) (SM1 on) Extend Transfer Cylinder (SOL1 on) 4 Transfer cylinder extended (MR2 on) Retract Transfer cylinder 5 Transfer cylinder retracted (MR1 on) Cycle Ends Figure 109. Sequence of Operations 119

120 SKILL 9 DESIGN A PLC PROGRAM THAT SEQUENCES AN INDEXING STATION Procedure Overview In this procedure, you will design and test a PLC program that uses an indexing table, pick and place pneumatic manipulator, transfer module, and fiber optic gauging module to correctly orient parts as they progress through the station. 1. Design a PLC program given the following information. The general sequence, I/O diagram, and power diagram are as follows: General Sequence: 1) Pressing the Start button enables the PLC program which indexes the table/part (stepper motor go 45) 45 to the fiber optic gauging module. 2) Once the indexing table movement stops, the stepper motor controller energizes its motor ready output and the part is checked for orientation (port detect). 3) If the part is incorrectly oriented (Spool Upper Port Detection off), the manipulator reorients the part as follows. A. The indexing table/part is moved another 45 (Stepper Motor Go 45) to the pneumatic manipulator and stops. B. The pneumatic manipulator s y-axis retracts (SOL4B on). C. Once the y-axis is retracted (GMR3 on), the gripper closes (SOL2B on) and the valve body is grasped. D. After a very short time delay, the manipulator s y-axis extends (SOL4A on) and the manipulator lifts the valve body. E. Once the y-axis has extended (GMR4 on), the PLC looks at the gripper rotation sensors (MR5 CW and MR6 CCW) to determine which sensor is on to know which direction to rotate the gripper, then the gripper rotates 180 (SOL3A or 3B). F. After the gripper rotates 180 (MR5 or MR6 on), the y-axis retracts (SOL4B on). G. As the y-axis retracts fully (GMR3 on), the gripper opens (SOL2A on). H. After a short time delay, the y-axis extends (SOL4A on). I. After the y-axis extends, the indexing table/part is moved 90 to the transfer module. 4) If part orientation is correct (Spool Upper Port Detection on), the table is indexed 135 (energize 45 and 90 degree inputs). 5) Once a part arrives at the transfer module, the transfer cylinder extends (SOL1 energized). 6) Once the cylinder has fully extended, activating MR2, it will retract. 120

121 7) When the cylinder has fully retracted, activating MR1, the process will stop. Special Conditions: The sequence cannot be started unless the stepper motor is homed and stationary (motor ready signal on), y-axis is extended (GMR4 on), transfer cylinder retracted (MR1 on), and the part present sensor at the initial location (CS2) is on. The Start pushbutton lamp will be off when the manipulator is in its home position (y-axis extended, gripper rotated clockwise, and gripper fingers open) and the stepper motor is homed and stationary (motor ready signal on). The Start pushbutton lamp will turn solid as the station is operating. Pressing the Stop pushbutton at any time will cause the indexing processing station to stop (or halt) at the end of its current step. Pressing the Start pushbutton will resume the sequence from that step. An interlock (Stepper Motor Ready) is used to keep the transfer cylinder from extending unless the stepper motor is stationary. 121

122 PB1 I/O DIAGRAM START I0.0 Q4.0 ACTIVE LAMP PB2 STOP I0.1 Q4.5 TRANSFER (SOL1) RESET I1.0 Q4.6 LIFT EXTEND (SOL4A) MR1 AUTO I1.1 TRANSFER RETRACTED I1.2 Q4.7 LIFT RETRACT (SOL4B) MR2 GMR3 GMR4 CS1 MR5 TRANSFER EXTENDED I1.3 LIFT RETRACTED I1.4 LIFT EXTENDED I1.5 PART PRESENT ORIENTATION MODULE I2.1 ROTATION RETRACTED I2.2 Q5.2 Q5.3 Q5.4 Q5.5 Q5.6 Q5.7 STEPPER MOTOR GO 45 STEPPER MOTOR GO 90 GRIPPER RELEASE (SOL2A) GRIP (SOL2B) ROTATION EXTEND (SOL3A) ROTATION RETRACT (SOL3B) MR6 ROTATION EXTENDED I2.3 PS1 SPOOL UPPER PORT DETECTED I2.4 IND1 TABLE HOME POSITION I2.5 SM1 STEPPER MOTOR READY I2.6 CS2 PART PRESENT AT INITIAL LOCATION I2.7 Figure 110. I/O Diagram 122

123 FROM SOURCE SOL4A LIFT GMR3 RETRACTED SOL4B SOL3A GMR4 EXTENDED ROTATION MR5 HOMED SOL3B MR6 ROTATED SOL2A GRIPPER CLOSED SOL2B SOL1 OPEN TRANSFER MR1 RETRACTED MR2 EXTENDED FIBER-OPTIC SENSOR (PS1) CAPACITIVE SENSOR (CS1) STEPPER CAPACITIVE SENSOR (CS2) INDUCTIVE SENSOR (IND1) Figure 111. Power Diagram 123

124 INDEXING STATION SEQUENCE DIAGRAM - INCORRECT PART ORIENTATION INPUTS OUTPUTS Start PB (I0.0) StopPB(I0.1) MR1 (I1.2) MR2(I1.3) GMR3 (I1.4) GMR4 (I1.5) Step Input Action Output Action 0 Start Condition Receive Start Input Index Table 45 1/ 0 1 1/ 0 2 Stepper Motor Ready/Port Index Table 45 Detection Sensor Off 1/ 0 0 1/ 0 3 Stepper Motor Ready/Part Retract Y-Axis Present Sensor (CS1) On Y-Axis Retracted Close Gripper Gripper Closed Extend Y-Axis Y-Axis Extended Rotate Gripper Gripper Rotated Retract Y-Axis Y-Axis Retracted Open Gripper Gripper Opened Extend Y-Axis Y-Axis Extended Index Table / 0 11 Stepper Motor Ready Extend Transfer Cylinder 0 1/ Transfer Cylinder Extended Retract Transfer Cylinder Transfer Cylinder Retracted Cycle Ends End Condition CS1 (I2.1) MR5 (I2.2) MR6 (I2.3) PS1 (I2.4) IND1 (I2.5) Motor Ready (I2.6) CS2 (I2.7) Active Lamp (Q4.0) SOL1 (Q4.5) SOL4A (Q4.6) SOL4B (Q4.7) Motor Go 45 (Q5.2) MotorGo 90 (Q5.3) SOL2A (Q5.4) SOL2B (Q5.5) SOL3A (Q5.6) SOL3B (Q5.7) INDEXING STATION SEQUENCE DIAGRAM - CORRECT PART ORIENTATION INPUTS OUTPUTS Step Input Action Output Action 0 Start Condition Receive Start Input/Part Present Sensor (CS2) On Index Table 45 1/ Stepper Motor Ready/Port Detection Sensor On Index Table / 0 1/ 0 3 Stepper Motor Ready Extend Transfer Cylinder Transfer Cylinder Extended Retract Transfer Cylinder Transfer Cylinder Retracted Cycle Repeats End Condition Figure 112. Sequence Diagram Start PB (I0.0) Stop PB ((0.1) MR1 (I1.2) MR2 (I1.3) GMR3 (I1.4) GMR4 (I1.5) CS1 (I2.1) MR5 (I2.2) MR6(I2.3) PS1 (I2.4) 2. Perform the following substeps to open the PLC programming software. A. Make sure that the interface from the personal computer to the PLC is connected. B. Power up the PC and monitor. C. Start the SIMATIC Manager. 3. Perform the following substeps to create a project. A. Create a Project named L5S9XXX where XXX represents your initials. B. Create an S7 Station object for the station and configure its hardware. C. Open Organizational Block OB1. D. Enter the program that you developed in Step 1 into Organizational Block OB1. E. Save OB1. IND1(I2.5) Motor Ready (I2.6) CS2(I2.7) Active Lamp (Q4.0) SOL1 (Q4.5) SOL4A (Q4.6) SOL4B (Q4.7) Motor Go 45 (Q5.2) Motor Go 90 (Q5.3) SOL2A (Q5.4) SOL2B (Q5.5) SOL3A (Q5.6) SOL3B (Q5.7) 124

125 4. If the 87-MS3 Indexing station is connected to another station, separate the stations. If the 87-MS3 Indexing station is already disconnected, continue to Step Perform the following safety check before you begin working on the station. Make sure that you can answer yes to each item before proceeding. YES/NO SAFETY CHECKOUT Remove all obstructions from the work area Check for signs of damage to the equipment Wear tight fi tting clothing, roll up long sleeves, remove ties, scarves, jewelry, etc. Tie up long hair Remove any robot teach pendants from the work area Locate the emergency stop button Ensure that safety glasses are worn by people in area Ensure that all people are outside any work envelopes Figure 113. Mechatronics Safety Check 6. Connect an air supply line to the station s air manifold quick connect. 7. Plug the station s power cable into a power outlet. 8. Perform the following substeps to power up the 87-MS3 Indexing station. A. Remove the lockout/tagout device from the electrical power source. B. Remove the lockout/tagout device from the pneumatic power source. C. Turn on the air to the station by shifting the lever on the lockout valve. D. Set the station s air supply regulator to 50 psi/ 345 kpa. E. Turn the station s Main Power switch to the On position. 9. Press the Output Power pushbutton to enable the PLC s outputs. 10. Use the DCVs manual overrides to home the pneumatic manipulator (y-axis extended, rotation cylinder retracted, and gripper open). 125

126 11. Place a parts bin at the parts transfer module to capture the parts as they are transferred from the Indexing Table. 12. Perform the following substeps to download the project to the PLC. A. Reset the PLC. B. Download the SIMATIC 300 Station object to the PLC. Several dialogs will appear during the download. Click the appropriate response to continue downloading the program. The last dialog should ask if you wish to perform a complete (Warm) restart. C. Click Yes on the dialog to complete a warm restart. 13. Go online with the processor and monitor the OB1 Block. 14. Place a valve body right-side up at the indexing table s initial location as shown in figure 114. This should have no effect on the indexing station, as the Start pushbutton has not yet been pressed in in. Figure 114. Valve Body Placement 15. Press and release the Start pushbutton. The Start pushbutton s active indicator should turn solid indicating that the station is running. The indexing table/part should turn 45 to the fiber optic gauging module and stop. Because the part is correctly oriented, the indexing station/part should quickly turn another 135 so that the valve body is at the transfer module. After a moment, the transfer module extends and retracts, transferring the valve body into the parts bin. 126

127 16. Place another valve body in the upside down position at the indexing table s initial location, as shown in figure in in. Figure 115. Valve Body Positioned Upside Down 17. Press and release the Start pushbutton. The indexing table/part should turn 45 to the fiber optic gauging module and stop. This time, however, the fiber optic gauging module senses that the part is incorrectly oriented. The part is moved just 45 to the pneumatic manipulator. There, the manipulator reorients the part and returns it to the indexing table. Once the manipulator has completed its sequence, the part is transferred 90 so that the valve body is at the transfer module. After a moment, the transfer module extends and retracts, transferring the valve body into the parts bin. 18. Correctly orient a part at the initial location on the indexing table. 19. Press and release the Start pushbutton. 20. Once the Indexing station begins operation, press the Stop button to stop (or halt) the station after its current step. Once movement is complete, the station should stop. 21. Press the Start pushbutton. The station should resume operation from its current step 22. Perform the following substeps to shut down the 87-MS3 Indexing station. A. Close the LAD/STL/FBD Editor. B. Close the SIMATIC Manager. C. Turn off the PC and monitor. D. Turn the 87-MS3 s main power switch to Off. E. Perform a lockout/tagout on the system s electrical power source. F. Perform a lockout/tagout on the system s pneumatic power source. 127

128 OBJECTIVE 11 DESCRIBE THE OPERATION OF A INDEXING STATION WITH MANUAL/ AUTO/ RESET FUNCTIONS Traditional operator panels usually include 2-position or 3-position selector switches to select the mode of operation, as shown in figure 116. Some of the modes that can be selected are Off, Manual, Automatic, and Reset. Figure 116. Operator Panel with Selector Switches AUTOMATIC Selecting the automatic mode causes the PLC program to disable the manual functions and enable the automatic functions. This is usually done by disabling a manual function or function block and enabling an automatic function or function block. After automatic mode is selected, certain initial conditions are usually required to be satisfied before the station s sequence can begin. These initial conditions are input signals monitored by the PLC to verify that the station s parts are in the home position and to verify that a part is present and ready to be processed. If the station s parts are not in the proper position, a visual indicator is usually displayed on the operator panel to indicate that the station is not in its home position. If the station s parts are not homed, the operator must either switch to manual mode and reposition the parts, or initiate a reset function to home the station. After the machine is homed and the automatic mode is selected, pressing a start pushbutton causes the station to perform its sequence automatically. After the sequence has been completed, the station repeats the cycle. 128

129 MANUAL Selecting the manual mode causes the PLC program to enable the machine s manual functions. This is usually done in program logic by enabling a function or function block containing the manual operations while disabling functions and/or function blocks supporting the machine s other operating modes. Placing a machine in manual mode enables the user to move the machine s actuators on an as needed basis and is rarely used for production purposes. Because of this, the manual mode is usually associated with maintenance operations. Maintenance personnel may use the manual mode to: test the operation of a machine, make adjustments to the machine and/or its sensors, or to recover from a machine malfunction. There are two versions of manual operation: standard manual operation and step. Manual (traditional) - In this version of manual operation, turning the selector switch to the Manual position typically enables pushbuttons and/ or other manual operators on the operator panel to be used to manipulate the machine s actuators. In the case of a gauging station, for example, the operator panel (or HMI) could have two pushbuttons for each of the station s cylinders, one to make the actuator extend and one to make it retract. Step - In this version of manual operation, a pushbutton or other manual operator is used to step the machine through the steps of its sequence, one step at a time. In the case of a pick and place feeding application, pressing the pushbutton the first time would cause the system s feed cylinder to extend. Pressing the pushbutton a second time would cause the manipulator s Z-axis to extend, and so forth. RESET A reset function is included in the PLC program to home the station. The PLC program is designed to return all actuators to their start positions when a selector switch is placed in the Reset position. The reset function can be programmed to cause all of the actuators to return to their start positions at the same time or it can be programmed to return them in a sequence. Depending on the physical layout of the station, returning all of the actuators at the same time may cause some actuators to interfere with others. In this case, the reset function must be programmed to perform a reset sequence. Using a sequence causes the actuators to return to the home position in an order that prevents interference with other actuators. 129

130 For example, an indexing station s pneumatic manipulator s cylinder is extended. After the cylinder is extended, the gripper is rotated to its home position and the gripper is opened, as shown in figure 117. The cylinder is extended first so that the gripper does not contact the indexing table. The transfer cylinder is also retracted. When all of the stations parts are in the home position, an indicator is provided on the operator panel. The indicator may be a dedicated Home lamp, or solid, off, or flashing indicators on the panel s pushbuttons. GRIPPER ROTATED TO HOME POSITION EXTENDED GRIPPER OPEN Figure 117. Indexing Processing Station 130