L20 - Solve Your Application Challenges with New Sensing Solutions Hands-On Lab For Classroom Use Only!

Transcription

1 L20 - Solve Your Application Challenges with New Sensing Solutions Hands-On Lab For Classroom Use Only! Important User Information

2 This documentation, whether, illustrative, printed, online or electronic (hereinafter Documentation ) is intended for use only as a learning aid when using Rockwell Automation approved demonstration hardware, software and firmware. The Documentation should only be used as a learning tool by qualified professionals. The variety of uses for the hardware, software and firmware (hereinafter Products ) described in this Documentation, mandates that those responsible for the application and use of those Products must satisfy themselves that all necessary steps have been taken to ensure that each application and actual use meets all performance and safety requirements, including any applicable laws, regulations, codes and standards in addition to any applicable technical documents. In no event will Rockwell Automation, Inc., or any of its affiliate or subsidiary companies (hereinafter Rockwell Automation ) be responsible or liable for any indirect or consequential damages resulting from the use or application of the Products described in this Documentation. Rockwell Automation does not assume responsibility or liability for damages of any kind based on the alleged use of, or reliance on, this Documentation. No patent liability is assumed by Rockwell Automation with respect to use of information, circuits, equipment, or software described in the Documentation. Except as specifically agreed in writing as part of a maintenance or support contract, equipment users are responsible for: properly using, calibrating, operating, monitoring and maintaining all Products consistent with all Rockwell Automation or third-party provided instructions, warnings, recommendations and documentation; ensuring that only properly trained personnel use, operate and maintain the Products at all times; staying informed of all Product updates and alerts and implementing all updates and fixes; and all other factors affecting the Products that are outside of the direct control of Rockwell Automation. Reproduction of the contents of the Documentation, in whole or in part, without written permission of Rockwell Automation is prohibited. Throughout this manual we use the following notes to make you aware of safety considerations:

3 Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss. Identifies information that is critical for successful application and understanding of the product. Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you: identify a hazard avoid a hazard recognize the consequence Labels may be located on or inside the drive to alert people that dangerous voltage may be present. Labels may be located on or inside the drive to alert people that surfaces may be dangerous temperatures. Solve Your Application Challenges with New Sensing Solutions Hands-On Lab Contents Before you begin...5 About this lab...5 Tools & prerequisites...6 Introduction to the 42JT VisiSight, the 42CS, and the Background Suppression sensing mode JT VisiSight Background Suppression with visible red emitter...7 Simulation of a real application...9 Detection of other target materials JT Push Button Lock and Unlock JT VisiSight Background Suppression with Laser emitter CS Stainless Steel Photoelectric Sensor, Background Suppression Model Clear Object Detection of 33

4 Registration Mark (Color Mark) Sensing True Color Sensing with the 45CLR Small Object Detection FPL Fiber Optic Sensor LSP Optical Fork Sensor Distance Measurement Sensing LMS Long Range Laser Measurement Sensor BPD Short Range Laser Measurement Sensor M Ultrasonic Sensor... 30

5 Before you begin About this lab The Sensor Briefcase Demo features many high performance photoelectric and ultrasonic sensors from the Allen-Bradley portfolio. This self-contained demo includes targets for each sensor that are intended to show an example application. This lab walks the user through the basic set up of many of the sensors and discusses how the example applications tie back to real automation applications. The demo and lab feature many challenging sensor applications, including: Background Suppression: Detect dark targets on light background, often a challenge in applications where there is not a place to mount a reflector. Clear Object Detection: Sense a clear bottle or other clear target, such as a plastic film. Registration Mark Detection (Color Mark): Detect different color marks on various backgrounds. This type of application is common for a web of pre-cut labels and is used to align the cutting mechanism with the label printing on the web. True Color Recognition: Differentiate between colors (e.g. sorting green objects from blue objects). Small Object Detection: Compare the use of optical fork sensors with fiber optic sensors for the detection of small objects. Distance Measurement: Utilize laser measurement and ultrasonic sensors for precise distance measurement and position feedback applications. This lab takes approximately 80 minutes to complete. 5 of 33

6 Tools & prerequisites This lab requires only the Sensor Briefcase Demo. All sensors, targets, and power supplies are included in this demo and there are no loose parts. This lab does NOT require a PC or any software b d 9 3 a 8 3 c The Sensor Briefcase Demo includes the following photoelectric and ultrasonic sensors: 1. 45LMS Laser Measurement Sensor 2. 45FPL Fiber Optic Sensor 3. Several 42JT VisiSight Sensors, including: a. Clear Object b. Color Mark / Contrast with white emitter c. Background Suppression with standard red emitter d. Background Suppression with laser emitter 4. 45CLR Color Sensor 5. 45CRM Color (Registration) Mark Sensor with RGB emitter 6. 45LSP Optical Fork Sensor M Ultrasonic Sensor with 4-20 ma analog output 8. 45BPD Laser Measurement Sensor 9. 42CS Stainless Steel Background Suppression Sensor 6 of 33

7 Introduction to the 42JT VisiSight, the 42CS, and the Background Suppression sensing mode This section introduces the 42JT VisiSight and 42CS stainless steel photoelectric sensors. This section also introduces the Background Suppression sensing mode, a specialty type of diffuse sensor that is used for challenging applications. The most common sensing mode of photoelectric sensor is Polarized Retroreflective. This sensing mode consists of an emitter and receiver in a single housing. Light from the emitter is reflected by a reflector placed on the opposite side of the target. As the target passes through the field of view it blocks the reflected light, thus allowing the sensor to detect this target. Specially oriented polarizing filters in the sensor enable it to differentiate light reflected off the reflector from light reflected off a shiny target (such as a piece of polished metal), thus giving this sensing mode a very high reliability. Generally, if a standard photoelectric sensor is appropriate for an application, the polarized retroreflective mode would be the first choice. However, in some applications there is not a place to mount a reflector. One example would be detecting a target on a conveyor belt looking down from above. In these applications, polarized retroreflective is not an option. One alternative would be a standard diffuse sensor; however, there are some disadvantages to standard diffuse sensors. This type of sensor detects the light reflected by the target. The amount of reflected light is affected by many factors. For example, different color targets reflect different amounts of light. This means that a diffuse sensor will detect these targets at different ranges. Diffuse sensors are also more likely to be affected by a dirty environment. As dirt or grime builds up on the lens, the sensor detects less light, and therefore becomes less and less sensitive as the lens gets dirtier. As a result, diffuse is not considered to be a reliable detection mode for many applications. Background Suppression (BGS) is a specialty type of diffuse sensor. Special chips and lenses enable the sensor to basically have a certain amount of depth perception in addition to light level sensitivity. This allows the sensor to detect any target within a certain range while ignoring objects beyond that range (in the background hence the name Background Suppression ). This capability significantly reduces the issues that standard diffuse suffer from. Background Suppression sensors are far more reliable than standard diffuse sensors, especially in applications where different colored targets may be present. (That said, BGS sensors are still not as reliable as polarized retroreflective sensors; therefore, if it is possible to mount a reflector in the application it is almost certainly better to use polarized retroreflective for that application.) Early Background Suppression models had very short ranges, often 100mm (4 in.) or less. Newer developments have enabled longer ranges. In the Allen-Bradley portfolio, the 42BT background suppression sensor has up to 2m (6.5 ft) of range. In this lab and demo, the miniature sized 42JT BGS sensor has 400mm (16 in.) of range to white paper. These sensing ranges allow for BGS sensors to be used in more and more applications that used to require diffuse sensors. 42JT VisiSight Background Suppression with visible red emitter The 42JT VisiSight is a high performance photoelectric sensor in a small package. It is available in a wide variety of sensing modes with both visible red LED and laser emitter options. The bright, visible emitter beam simplifies alignment of the sensor as compared to traditional infrared (invisible beam) sensors. We will start with the background suppression (BGS) with visible red LED. The catalog number of this sensor starts with 42JT-B2 It is towards the lower right hand corner of the demo case. 7 of 33

8 The target for this sensor features four different surfaces, each a different color or material. The purpose of having four different options is to show how the BGS sensor will detect each of these at the same range, while ignoring each when they are beyond this range. This would not be possible with a standard diffuse sensor each surface would be detected at a substantially different distance. The target can rotate and also slide up, down, left and right. The built in ruler gives us a simple reference for comparing the detected ranges. 1. Rotate the target so that the flat black side is facing the 42JT-B2 sensor. 2. Move the target up or down on the vertical track until it is at the 8 cm position on the ruler (approximately 3¼ inches). Note that it is easiest to move the target up and down by grabbing and applying force to the middle of the horizontal (moveable) track, as opposed to pushing the target itself. 3. Confirm that the entire red beam is on the black target. (It is a square pattern and should be very clear at this distance.) 4. On the 42JT-B2 sensor, push and hold the teach button for three seconds until the yellow LED starts flashing. Release the button. The first condition is now taught. t > 3 s 5. If the yellow LED does not start flashing after several seconds of holding the button, the push button may be locked. In this case, skip ahead to the next section for instructions on how to unlock the teach button and then return to the previous step once it is unlocked. 6. Slide the target 2 cm further away from the sensor to the 10 cm position on the ruler (approximately 4 inches). This represents our background position that we want the sensor to ignore. 7. Press and release the teach button. This teaches the second condition. The yellow LED will stop flashing. The teach process is complete. Note that if the push button is not pressed again within 30 seconds of starting the teach mode, the sensor exits the teach mode. The yellow LED will stop flashing. If the yellow LED stops flashing before you push the teach button the second time, please start the teach process over from step 1. 8 of 33

9 8. Slide the target towards the sensor. Make a note of the distance that turns ON the sensor output with this black target. Note that this Turn ON distance is between the taught target distance and background distance. 9. Slide the target away from the sensor. Make a note of the distance that turns OFF the sensor output with this black target. The difference between the Turn ON and Turn OFF point is the hysteresis. Note: The green LED may flash when the target is close to the switching threshold distance. This flashing indicates that the detected light signal is very close to the switching threshold. In a real application, if the green LED was flashing for either the target or the background it would indicate that the sensor might not consistently work in the application. In this situation, the user should consider making additional adjustments to the target, the background, and/or the position of the sensor to try and improve the stability of the light signal. 10. Slide the target to the left and then rotate the target so that the white side is facing the sensor. 11. Slide the target back to the right so that the 42JT beam is entirely on the white surface. 12. Confirm that the 42JT output is OFF. If it is ON, slide the target away from the sensor until it turns OFF. 13. Now slide the target towards the sensor. Make a note of the distance that turns ON the sensor output with this white target. How much difference is there between the turn ON distance for the black target and the turn ON distance for the white target? 14. Slide the target away from the sensor. Make a note of the distance that turns OFF the sensor output with this white target. Simulation of a real application 15. Let s compare this to a real application. We are trying to detect a 2 cm tall black object on a white conveyor that is 10 cm away from the 42JT-B2 Background Suppression sensor. Will we be able to consistently detect this target? 16. To prove this application will work consistently, let s use our setup to simulate the application. With the white side towards the sensor and positioned 10 cm away from the sensor, slide the target to the left and right, moving it in and out of the sensor s field of view. The sensor s output should remain OFF. 9 of 33

10 Here is an illustration of moving the target to simulate a real application. Written description continues in the next steps. 17. Rotate the target so that the flat black side is facing the sensor and position it 8 cm away from the sensor 18. Slide the target left and right, in and out of the sensor s field of view. Does the sensor turn ON each time the target comes into its field of view? 19. The sensor should consistently turn ON for the black target at 8 cm, while it should remain OFF for the white target at 10 cm. This sensor should work well in this simulated application. Note: The white background target (simulating the conveyor) reflects substantially more light than the dark target. For this reason, a standard diffuse sensor would not consistently detect the black target and therefore would not work well in this application. This is one example of an application in which background suppression is far superior to standard diffuse. Detection of other target materials 20. Rotate the target so that fuzzy black side is facing the sensor. The surface reflects even less light than the flat black side, and therefore is an even more challenging target for a diffuse photoelectric sensor. 21. Slide the target towards and away from the sensor. Make a note of the turn ON and turn OFF distances of the fuzzy black target. How do these ranges compare to the white and flat black targets? 22. Rotate the target so that shiny side is facing the sensor. Shiny surfaces reflect substantially more light than matte white surfaces. This makes shiny surfaces particularly challenging targets for photoelectric sensors. 23. Slide the target towards and away from the sensor. Make a note of the turn ON and turn OFF distances of the shiny target. How do these ranges compare to the white and flat black targets? Would the 42JT-B2 BGS sensor be able to ignore a shiny background in this application? Note: Even though the BGS sensor can consistently ignore the shiny background surface in this example, it is important to understand that shiny objects in the background can cause application challenges for photoelectric sensors, even background suppression models. If there is a shiny object in the background, be sure to thoroughly test the application. If it is possible to align the sensor so that the shiny background is no longer 10 of 33

11 in the sensor s field of view, or so that the sensor beam hits the shiny background at an angle instead of perpendicular, the application is more likely to be successful. 42JT Push Button Lock and Unlock Sensors with teach or manual adjustment are flexible and can be used in many applications; however, some engineers do not like the idea of an operator or maintenance person making changes to the settings of a sensor after the initial setup. These engineers often ask for fixed range sensors. Another potential solution is to prevent adjustment by locking the teach button. The push button on the 42JT can be locked two different ways. A permanent lock can be achieved by attaching the white wire (pin 2) to 0 V. If the white wire is connected to 0 V, the push button is completely ignored by the sensor and no changes can be made. By taking advantage of this feature, the engineer originally applying the sensor can greatly reduce the likelihood of the settings of the sensor later being changed. A second option for locking is a simple push button sequence as documented in the following steps. 1. Press and release the teach button three times within three seconds. Both LEDs flash synchronously for three seconds, indicating that the teach button is now locked. 2. Confirm that the teach button is locked by pressing and holding the teach button for more than three seconds. Normally this would put the sensor into teach mode and teach the first condition which would be indicated by the yellow LED flashing; however, because the teach button is locked, the LEDs will not start flashing, and the sensor never enters the teach mode. 3. To unlock the teach button, again press and release the button three times within three seconds. The green and yellow LEDs flash asynchronously to indicate that the push button is now unlocked. Note: this procedure will NOT unlock the sensor if it is permanently locked via the white wire (pin 2). The permanent lock can only be released by disconnecting the white wire from 0 V. 42JT VisiSight Background Suppression with Laser emitter Some photoelectric sensors utilize a laser instead of a standard LED for the emitter. Applications that could potentially benefit from using laser sensors include the detection of small objects and high precision applications. The 42JT VisiSight family includes laser versions of the transmitted beam, polarized retroreflective, standard diffuse, and background suppression sensing modes. The Sensor Briefcase Demo includes the laser background suppression model (42JT-B8 ), which is the second sensor from the right side of the demo. 11 of 33

12 1. Rotate the target so that the window with strings is facing the sensor. The string is an example of a small object that would be easier to detect with a laser sensor than a standard sensor. The string will be the target for the sensor in this lab. 2. Move the target up or down on the vertical track until it is at the 8 cm position on the ruler. 3. Confirm that the entire red laser spot is positioned on the string. 4. On the 42JT-B8 sensor, push and hold the teach button for three seconds until the yellow LED starts flashing. Release the button. The first condition is now taught. t > 3 s 5. Slide the target slightly to the right so that the laser beam goes between the strings. This represents our background position that we want the sensor to ignore. 6. Press and release the teach button. The yellow LED will stop flashing. The teach process is complete. 7. Slide the target right and left on the horizontal track. Note that the 42JT-B8 turns its output on not only for the strings, but also for the black frame, and the side of the perpendicular black target. The background suppression capability of this sensor enables to detect small light and dark targets at approximately the same range. 8. Compare the turn ON and turn OFF distances for each of the four sides of the rotating target (string, solid white, solid black and shiny). You will notice that the background suppression sensor has very consistent turn ON and turn OFF points for the different target colors. 42CS Stainless Steel Photoelectric Sensor, Background Suppression Model The 42CS photoelectric sensor family has a number of features particularly beneficial to Food & Beverage applications, including: 316L Stainless steel housing (plastic lens and connector) Optional smooth barrel housing to minimize food capture points 12 of 33

13 Wider temperature rating (-25 to + 85 C / -13 to 185 F) IP69K High temperature wash-down rating Ecolab certification for resistance to harsh cleaning chemicals often used in Food & Beverage applications The sensor briefcase demo includes a smooth barrel background suppression 42CS at the far right. The 42CS is taught using a ferromagnetic object (such as a screwdriver). The user touches the screwdriver to a specific teach area near the connector. (A metal rod ships with the sensor to use as a teach device.) Teaching the sensor requires a metal object, which is not included in the demo kit (but is typically readily available in most real applications). With that in mind we will not teach the sensor, but simply observe the performance of the sensor. 1. Familiarize yourself with the LED indicators of the 42CS. LED Status OFF Teach function locked Green ON Teach function is enabled Flashing (8 Hz) Short circuit OFF Output de-energized Yellow ON Output energized Flashing (3 Hz) Output energized (Margin < 2x) 2. Rotate the target so that the black side is facing the sensor. 3. Confirm that the 42CS emitter beam is on the target. 4. Slide the target up and down the rail. Note the distance that causes the sensor output to turn ON. 5. Slide the target to the left so that it is not in the sensing area of the 42CS. 6. Slide the target away from the sensor, and then rotate it so that the white side is towards the sensor. 7. Slide the target to the right so that the sensor s emitter beam is on the target. 8. Slide the target towards the sensor until the sensor turns its output ON. Did the white target turn the sensor ON at the same distance and the black target? 13 of 33

14 9. Different background suppression sensors offer different performance and each should be tested in the application. That said, background suppression sensors will consistently offer better performance than standard diffuse sensors in the vast majority of applications. Clear Object Detection Clear objects are inherently challenging targets for photoelectric sensors. Standard photoelectric sensing modes will not work consistently for the detection of clear objects. That said, specialty sensing modes have been developed specifically for the detection of clear objects. The 42JT family includes a high performance clear object photoelectric sensor. This particular model is a specialized form of polarized retroreflective. The sensor and reflector are in the lower left corner of the Sensor Briefcase Demo. 1. Move the clear target to the right so that it is out of the sensor s field of view. 2. On the 42JT-C2 Clear Object sensor, push and hold the teach button for three seconds until the yellow LED starts flashing. Release the button. The reflector is now taught. t > 3 s 3. If the yellow LED does not start flashing after several seconds of holding the button, the push button may be locked. In this case, flip back to the earlier section that explained the lock and unlock process (on page 10). 4. Slide the target to the left so that the red sensor beam passes through it. 5. Press and release the teach button. The yellow LED will stop flashing. The teach process is complete. 6. Slide the target to the left and right. The output turns ON when the clear object is detected and OFF when the clear object is not present. The sensor will also detect any opaque target, such as your hand. Because the opaque object blocks all (or almost all) of the emitted light, it is an easier object for the sensor to detect. This means that the sensor could be used in an application which sometimes has clear bottles and other times has green, brown, or other color bottles, all without having to reteach the sensor. Be sure to test the application for all potential target colors and materials. 14 of 33

15 Registration Mark (Color Mark) Sensing Many labels and wrappers are originally printed on long continuous sheets that are then rolled up. The machine that packages the item then unrolls the web of labels, cuts them to size, and completes the packaging of the individual item. For example, a candy wrapper might look something like the following image before it is cut. Because the printing and cutting of this web happen at different times, the cutting machine must know how the printing lands on the web. Otherwise it would not be possible to cut the web in the right spot. A candy bar might come out of the machine looking like the following image. The key feature that enables the packaging machine to avoid this problem is the use of a registration mark on the label. This mark is of a contrasting color and is always printed on a linear section of the label that is otherwise a solid color. On this label, we see a white mark near that upper edge. A specialized photoelectric sensor, typically called a color mark sensor or registration mark sensor, is used to detect these marks. It is a contrast sensor, detecting the difference in the amount of light reflected by the web in a small area. These sensors have short sensing ranges (10-20 mm) and small emitter light spots (typically 2 to 5 mm2). In this application, the sensor would be positioned with the light spot at the upper edge of the label. As the label passes from left to right, the sensor would normally see just brown, and then see white as the mark passed through the detection area (light spot). This small white area would reflect much more light than the brown, thus enabling the photoelectric sensor to detect it. The sensor would then send a signal to the machine so that any cutting mechanism could be aligned with the print. This spot must be a different color for the sensor to detect it. The more contrast between the mark and the background, the easier it is for the sensor to detect it. Dark labels will typically have white registration marks, while light labels will typically have dark registration marks. Here are a few examples. 15 of 33

16 The Allen-Bradley portfolio of sensors includes a few registration mark sensors. Two of them are included in the Sensor Briefcase Demo near the registration mark target. One model is part of the 42JT VisiSight family. This model uses a white emitter and is suitable for most registration mark applications. The other is the high end 45CRM sensor. This model features red, green, and blue emitters the sensor picks the best emitter color during the teach process. (This selection is automatic and sensor selects the emitter color that maximizes the contrast between the mark color and the background color.) The 45CRM will solve challenging applications beyond the capability of the 42JT model, such as a light yellow mark on a darker yellow background, or marks on very shiny print labels. In this lab we will set up the 42JT for a few different applications. 16 of 33

17 1. Rotate the target so that the white label with black marks is facing the sensors. 2. Move the target to the right until the white light spot of the 42JT-F5 is on a black registration mark. The 42JT is the middle sensor of the three rectangular sensors. Its light spot is approximately 1 mm wide and 5 mm tall. 3. On the 42JT-F5 registration mark sensor, push and hold the teach button for three seconds until the yellow LED starts flashing. Release the button. The registration mark is now taught. t > 3 s 4. If the yellow LED does not start flashing after several seconds of holding the button, the push button may be locked. In this case, flip back to the earlier section that explained the lock and unlock process (on page 10). 5. Slide the target to the left or right until the white light spot is on the white background. 6. Press and release the teach button. The yellow LED will stop flashing. The teach process is complete. 7. Slide the target to the left and right. The output turns ON when the mark is detected and OFF when the light spot is on the normal web color (in this application, white). The sensor automatically configures itself to be Light Operate (LO) or Dark Operate (DO) based on whether the first taught condition is lighter or darker, respectively, than the second taught condition. In this application, the sensor is configured for Dark Operate the registration marks are dark and reflect less light than the white web color. In most applications, the user prefers the sensor output to normally be OFF and then turn ON for the mark, as we set up above. In other applications, the user prefers the sensor output to normally be ON and then turn OFF when the mark is detected. The 42JT-F5 can be set up for either. The easiest way to do this is to teach the normal color first, then teach the mark. The sensor will turn ON when it detects the normal web color (white for this target) and turn OFF when it detects the mark (black in this application). 17 of 33

18 8. Registration Mark applications are often found on packaging machines that use different labels at different times. If the web (label) is changed, the color of the label and / or registration mark may change. If this color combination changes, we must reteach the sensor. Let s simulate this by teaching one of the other registration mark examples. Rotate the target so that the shiny label with red marks is facing the sensor. 9. On the previous target, we used the static teach method, where the mark and the background are individually taught. For this target, we will use the dynamic teach method. The dynamic teach mode is used when the web is continuously moving during the teach process. 10. Slide the target to the right until the 42JT-F5 light spot is on the shiny label material. t > 3 s 11. On the 42JT-F5 registration mark sensor, push and hold the teach button for three seconds until the yellow LED starts flashing. Release the button. The sensor is now in the teach mode. While the sensor is in teach mode, it is continuously monitoring and recording the detected light signal. 12. Slide the target left and/or right so that the light spot passes over at least two red registration marks on the shiny background. The sensor must see two cycles of mark and background to accomplish the dynamic teach within 30 seconds of the first teach button push. Also, be sure that the sensor only detects label and mark do not move the target so far that the light spot is completely off the label. (In a real application, it is important that the sensor only sees a consistent target condition and a consistent background condition, with minimal variation within each of those conditions. This would be typical for registration mark applications on a continuous web material.) 13. After 30 seconds, the yellow LED will stop flashing. The dynamic teach is complete. 14. Slide the target left and right. Note that the output turns ON when the sensor detects a mark and OFF when it detects the background (shiny material). Note: Unlike the static teach method, in dynamic teach mode the 42JT registration mark sensor maintains the selection of LO or DO from the previously configured settings. (The default is LO.) If the user wishes to invert an LO signal to DO or vice versa, this can be toggled by pushing and holding the teach button for 6 seconds until the green LED starts flashing. Pushing the teach button again toggles the LO or DO setting. (Repeated button pushes continue to toggle the setting.) Exit this mode simply by waiting 10 seconds after the last push of the button. 15. You may have noticed that the Registration Mark sensors are positioned at a slight angle to the target. This improves the sensor reliability, particularly for challenging applications such as the shiny label from the previous steps. If the sensor was pointed directly at this shiny target, it probably wouldn t work very well. In real applications it is best practice to position a registration mark sensor with this slight angle, as shown in the demo kit and the following illustration. 18 of 33

19 True Color Sensing with the 45CLR The 45CLR is a true color sensor it turns its output on only when it detects one specific, taught color. The 45CLR has three separate discrete outputs, allowing it to detect three different colors. A color sensor is useful if one needs to confirm a specific color. For example, in a bottling application where caps of several different colors are used, and the user wants to make sure that the correct cap was applied at a given time. Another application would be sorting by color. True color sensors typically have very short ranges. The 45CLR has a range of up 32mm (just over an inch), depending on the model. The 45CLR is located just to the left of the 42JT Registration Mark sensor from the previous section. 1. Rotate the target so that the side with multiple colors is facing the sensors. 2. The 45CLR has three discrete outputs, each of which are wired to an indicator light near the connector of the sensor. Slide the target left and right so that the white emitter light spot is positioned on each of the different colors. Each indicator will turn ON for just one color. Make a note of which color turns ON Channel 1 (CH1). (This will be whatever the previous user set it up for.) 3. Position the target so that the light spot is entirely on one color (preferably NOT the color that currently turns on Channel 1). 4. Familiarize yourself with the push button and indicator LEDs of the 45CLR. 19 of 33

20 Green Indicator LEDs Yellow Output Channel LEDs SET Button Button Red Tolerance LEDs 5. Press SET for 3 seconds until the green LED turns off and the Ch. 1 yellow LED turns on. 6. Select Channel 1 by pressing SET for 3 seconds until the middle red Tol. LED turns on. 7. Select Medium Tolerance by pressing SET for 3 seconds until the red Tol. LED turns off. This will exit the teach process and save the settings. 8. Confirm the sensor output operates for the taught color. Position the target so that the white spot is entirely on the card. The yellow Ch. 1 LED turns on. 9. Position the target so that the white emitter spot is on other colors. Do any other colors turn the CH1 output on? The tolerance of the 45CLR sensor can be changed if necessary for a specific application. This capability is beyond the scope of this lab, but is documented in the installation instructions of the sensor. Small Object Detection The detection of small objects can be a challenge for sensors. Over the years, many specialty sensors have been developed for better detection of small objects. Photoelectric sensor solutions include laser emitters, fiber optic sensors, and optical fork sensors. In this section we will show the latter two and compare these solutions. 45FPL Fiber Optic Sensor Fiber optic sensors use fiber optic cables to carry a light signal between the target area and a remote sensor. This allows for the detection of targets where it is not possible to get a sensor, due to size constraints, temperature, or inaccessibility. Fiber optic sensors may also be used in applications to simplify set up if the detection area is not easily accessible, with the sensor itself in a more accessible place. Another common application of fiber optic sensors is for the detection of small objects. The small 20 of 33

21 fiber tip makes it possible to use the sensor to detect small objects. Typically the fiber cables are set up in a transmitted beam fashion, with separate emitter and receiver fibers pointed at each other. Both fibers are connected to a single sensor which includes both the emitter and receiver elements. In this section we will set up the 45FPL fiber optic sensor to detect a piece of string, an example of a small target. The 45FPL is located towards the upper left of the demo. The fiber optic cables run from this sensor to the location of the target near the middle of the demo. Notice that the fiber optic cable tips are arranged in a transmitted beam orientation, with an emitter beam and a receiver tip. The U shaped bracket positions these tips towards each other. The target has a window with a few strings across the window the small targets will pass through this area and interrupt the sensing beam, allowing them to be detected. 1. Familiarize yourself with the indicators, buttons and switches of the 45FPL. See below for description Multidirectional 2. Lift the hinged cover of the sensor up and away from the control interface. Teach Indication push button Output delay 3. In this application we want the selector Mode output to indication turn ON when the target is detected. When the target interrupts the beam, this is the Dark condition; therefore we want the sensor to be in the Dark Operate (DO / D.ON) mode. Confirm that the D.ON/L.ON switch is in the left hand position towards D.ON. Output indication 4. The digital display indicates the light level received Threshold/Light received indication LO/DO slide switch on a scale of 0 to With the tips pointed at each other across a short distance, if there is nothing blocking the beam the light level is probably Slide the target left or right until the string is interrupting the beam. When the string is completely blocking the beam, you will see the light level displayed drop significantly. Very small changes in the position will result in large changes of the light level if the string is only partially blocking the beam, the detected light level may still be The string must be positioned in the exact center of the beam to effectively decrease the detected light. Determining this exact position will require moving the target slowly through the beam. 21 of 33

22 5. While the string is interrupting the beam we will start the teach process. Press and hold the green button for three seconds. The indicator will count 1, 2, 3, and then SEt, indicating that the first condition is taught, and then will display the current detected light level. Release the teach button. The Green Teach Indication LED will also be flashing, indicating that the sensor is in teach mode. 6. Slide the target so that the string is no longer interrupting the light beam. The light level display will show 8000 maximum light detected. Push and release the green teach button to teach the second condition (no target present). 7. The digital display will indicate one of the following conditions: Good Optimal teach conditions High Maximum sensitivity is set Hard Not enough difference between the light level detected for the two teach conditions Satu The receiver is saturated, i.e. it is receiving too much light for proper sensitivity adjustment 8. In most applications we are trying to get the Good indication as feedback during the teach process. If the sensor displayed Hard or Satu, redo the teach process. In a real application, if several teach attempts did not result in Good feedback we would consider adjusting the position of the fiber optic tips or making another adjustment to the application. 9. Slide the target left and right. As the string passes through the detection beam, you should see the 45FPL indicator (near the sensor) turning ON. 10. One advantage of a fiber optic sensor with a digital display is that it is easy to know what the sensor is seeing based on the indicated light level. It is also easy to check and adjust the threshold. Press and release the green push button. The digital display now indicates the threshold light level. This threshold is in between the light levels detected by the sensor for each taught condition. 11. In this application, we know that the sensor will detect the maximum light level (8000) when the target is not present. Therefore we could adjust the threshold to a relatively high value which would make it easier for the sensor to detect the target. The last digit of the display should be flashing. We could make minor adjustments of the threshold by pushing the multi position green button towards + or - (up left or down right, respectively). 12. For our application, we actually want to make a more significant change to the threshold. Push the multi position green button towards (down left) three times to change the digit that is flashing to the most significant digit. The and make it easier to make both large and small adjustments with a single button. 13. Using the green multi position button, adjust the threshold to approximately Press and release the green button in the middle position to return to the light level display view. 14. Close the hinged cover on the 45FPL. The sensor is now set up for this application. 22 of 33

23 The 45FPL has a dynamic teach method which is beyond the scope of this lab, but is documented in the installation instructions, along with other advanced functionality. 45LSP Optical Fork Sensor Optical fork sensors are basically a transmitted beam pair in a single housing. The emitter is in one leg of the fork, while the receiver is in the other leg. Objects passing through the fork interrupt the beam and are detected by the sensor. There are several advantages to optical fork sensors. The transmitted beam arrangement is a very consistent, reliable sensing mode. Furthermore, having a single housing makes the sensor very easy to install. For most applications, no sensitivity adjustment is required. The 45LSP is located next to the fiber optic tips in the middle of the demo. The 45LSP optical fork sensor can be used for many applications, including the detection of small objects. Because the factory default setting of the 45LSP is for maximum stability, it is sometimes necessary to teach the sensor for small or translucent objects. The easiest way to do this is to teach the sensor for maximum sensitivity. The following steps document this process. 1. Move the target so that nothing is blocking the light beam. 2. Press the teach button for approximately three seconds until orange LEDs are flashing synchronously. This teaches the first condition. 3. Do not move the target we still do not want to have anything blocking the beam. Press the teach button again for one second. This teaches the second condition. Because the sensor detected the full emitter light for both taught conditions, it sets itself to maximum sensitivity. In this state, the 45LSP can consistently detect objects as small as 0.2mm in diameter. 4. Slide the target left and right. The output indicator turns ON when the string interrupts the detection beam. Note that both sides of the fork sensor also light up to indicate the status of the output. This makes it very easy to see the sensor status, even if the sensor is further away or partially obstructed, making it very easy to troubleshoot when installed on equipment. 5. The sensor is ready to operate in this application. 23 of 33

24 One important note in this small object detection lab using a 45LSP optical fork sensor is substantially easier than using a fiber optic sensor. While the fiber optic sensor does have more flexibility, the fork sensor is often a better solution because of its simplicity. Keep in mind that in the demo kit, the bracket for the fiber optic cables is already set up. In real applications, you would have to mount and align each tip. If either fixture was bumped during production, it would be very difficult to troubleshoot the issue. We also need to run fiber cables back to the sensor, and perhaps protect those fiber cables from damage. Compare this to the fork sensor. With the fork, we only have to mount one housing. A quick disconnect provides easy electrical wiring. In most applications, no teach is required. Even for the few applications that do require a teach, the teach process is very simple. When the machine is running, it is very easy for anyone to look at the sensor and understand that it is working, thanks to the bright status LEDs on both sides. Furthermore, if the sensor was bumped out of the correct position, it is easy for any maintenance person to quickly identify and correct this issue. The fork sensors are available in various sizes to accommodate a variety of applications (30mm, 50mm, 80mm and 120mm). The point is be sure to consider the fork sensor for simplifying many small object detection applications traditionally solved with fiber optic sensors. Distance Measurement Sensing The Sensor Briefcase Demo includes several measurement sensors. These sensors measure the distance to the target and then communicate that distance via an analog signal to the control system. In the demo a small display shows this analog value. A three position selector switch next to display is used to select which sensor s output is shown. The demo includes the following measurement sensors: The 45LMS long range laser measurement sensor. This model has a sensing range of up to 15 m (49 ft) and utilizes a Class 2 laser emitter. (A different model with a Class 1 laser has a range up to 8 m / 26 ft range.) The 45BPD short range laser measurement sensor. This model has a sensing range of 300mm (approximately 12 inches) and utilizes a Class 2 laser. The 873M ultrasonic sensor with analog output. This model has a sensing range of 300mm (approximately 12 inches). (A different model has a range of 800mm / approximately 31 inches). 45LMS Long Range Laser Measurement Sensor The 45LMS is a great sensor for measurement applications requiring a diffuse operating mode (no reflector) and a range of up to 15 m (49 ft). Furthermore, this sensor can also be considered for discrete (on/off) applications, delivering performance similar to background suppression, but for much longer sensing ranges. The 45LMS is located in the upper left corner of the Sensor Briefcase Demo. In this lab we will observe the status of the discrete and analog outputs of the sensor. 24 of 33

25 1. The 45LMS has an ON/OFF selector switch on the panel next to it. Use this switch to turn on the 45LMS. You will see the laser emitter and green power indicator LED turn ON. 2. Familiarize yourself with the sensor s power and indicating LEDs. The 45LMS has several LED indicators to indicate output status and settings. See below for description. Note that the orientation in the demo kit will appear upside-down relative to this image. The Discrete Output The discrete output of the 45LMS is typically used in one of two modes, Switch-point and closer or Switching window. The former is the most commonly used mode for object detection with background suppression. If using the sensor for this type of application set the Teach-point at the farthest distance from the sensor that the target will pass. When using this mode, the sensor output will turn on if it detects an object between 200 mm (8 in.) from the sensor face and up to the Teach-point. For example, if the Teachpoint is set at 2 m (6.6 ft.), the output would turn on if the sensor detects an object anywhere between 200 mm and 2 m. Other discrete applications may utilize the switching window mode. When setting the sensor this way, the output will turn on when it detects an object within a window created between two set points. For example, if the set-point for Q1-A is set at 2 m, and the Teach-point for Q1-B is set at 3 m, the sensor will turn the output on if it detects an object between 2 and 3 m. 1. Use your hand as the target for the sensor. Place your hand approximately 300mm (1 ft) in front of the sensor. You should see the red laser beam on your hand. 25 of 33

26 2. Move your hand away from the sensor, keeping the laser beam on your hand. Observe the discrete output indicator. Continue moving your hand away from the sensor until the discrete output turns OFF. This represents the Q1B set point that was previously taught to the sensor. 3. Use any other available targets (e.g. chair, cell phone case, notebook) and confirm that the sensor turns on for a target at the same distance, regardless of the target material. 4. The following steps include instructions for setting up the discrete output. For the purposes of this lab consider the rest of this section to be optional. Setting up the discrete output requires a small screwdriver. If you do not have access to a screwdriver or if you are not interested in setting up the discrete output, please skip ahead to the next section, titled The Analog Output. 5. We will set up the discrete output using the Switch-point and closer mode described above. Place a target at the desired Teach-point. In a real application, we would want to position the target at the farthest point we anticipate the target to be during run mode or even just beyond that distance if possible. (Once in run mode, the sensor output will be OFF for anything detected beyond the range we are currently teaching.) 6. Use a small screwdriver to rotate the Rotary Switch so that the white arrow is pointed at the dot labeled Q1-B. 7. Press and hold the SET button until the Green and Yellow LEDs flash simultaneously. After the LEDs flash simultaneously, they flash alternately to indicate whether the Teach was successful. A successful teach is indicated by slower alternating flashing (2.5 Hz), while an unsuccessful teach is indicated by faster alternating flashing (8 Hz). (If the teach was unsuccessful, the settings revert to the previous valid configuration.) 8. If the Teach is successful, rotate the Rotary Switch so that the white arrow is pointed at the dot labeled RUN. 9. Using your hand as a target, move it towards and away from the sensor while observing the sensor output indicator to confirm that the discrete output is operating as expected. 10. Next we will observe the status of the analog output. The Analog Output The 4 20 ma output can be defined as any range within 200 mm to the maximum range of the sensor, as either a rising or falling slope, as described below. The default analog output setting for Q2 is A = 200 mm (8 in.) and B = 5,000 mm (16 ft) for all sensor models. The minimum window for setting the analog span is 21 mm (0.83 in.), although it is recommended to simply use the default settings for measurement applications requiring up to 5000mm (5m) of range. In the Positive Slope mode (also called Rising Slope) a target positioned at the closer set-point results in an analog output of 4 ma while a target at the farther set-point results in an output of 20 ma, with the analog output scaled linearly in between. In this mode, the sensor will output 20 ma when the target is outside of the operating range, which is mm (0 8 in.) and anything greater than the maximum sensing range. See the illustration for clarification. 26 of 33

27 1. Position the selector switch next to the analog display so that it is pointed at 45LMS (left position). The screen now displays the 4-20 ma analog output of the 45LMS (scaled from ). 2. Position a target (e.g. your hand) so that the 45LMS laser beam is on it. Move the target closer to and further from the sensor while observing the analog output on the digital display. Does the output match the illustration? (A 4mA output from the sensor will show as 0 on the digital display, while a 20mA output will display as 1000). 3. Use other available targets to confirm that the analog output is not affected differently by different target materials. 45BPD Short Range Laser Measurement Sensor The 45BPD is a useful sensor for high precision applications that require a sensing range of up to 300mm (approximately 12 inches). The 45BPD is typically appropriate for applications that require +/- 0.3mm of repeatability. Some target materials will enable the sensor to perform with even tighter repeatability as is often the case with specialty sensors, it is appropriate to test the sensor in the application to confirm the performance is acceptable. The 45BPD is located near the middle of the Sensor Briefcase Demo. The model in the demo has a sensing range of 80 to 300mm. This sensor cannot detect objects less than 80mm from the sensor face. (A different model has a sensing range of 30 to 100mm for shorter range applications.) Note that the target in the demo can be moved closer to the sensor than 80mm in this case, the sensor does not detect the target, therefore the discrete and analog outputs are not defined. It is easy to know if the target is within the detection range a small green LED labeled OK turns ON when the sensor can see the target (i.e. the target is within the detection range and is reflecting enough light for the sensor to detect it). How this target detection affects the sensor outputs is dependent on the initial teach process of the sensor. 1. Familiarize yourself with the LED indicators and teach buttons on the 45BPD. The first illustration shows LED status while the sensor is in run mode. The second illustration shows LED status while the sensor is in teach mode. 27 of 33

28 2. First we will complete a Factory Reset to return the sensor to its original settings. Press SET and simultaneously for 3 seconds to begin the Teach process. (The green LED Power/Teach-In will begin blinking). 3. Press the button four times until the R LED turns ON. R is for Reset. 4. Press SET to initiate a reset to factory defaults. The red Status LED will turn ON to confirm the reset. 5. Press SET and simultaneously for 1 second to exit the Teach mode and begin sensor operation. The green power/teach LED will stop flashing after the buttons are released, indicating that the sensor is in operating mode. 6. Confirm that the sensor is using the factory default settings, including: The discrete output and Q LED are ON when a target is detected within the sensor s mm sensing range and OFF when no target is detected. Note that the sensor beam will detect the side of the case when the target is not blocking the laser beam and therefore the output will be ON. Position the target so that it is less than 8cm (80mm) from the sensor this is the blind zone of the sensor, so the output should be OFF. The analog output will be scaled for the full sensing range of mm. The analog output has a negative slope the further the target, the lower the output. (Keep in mind that the sensor is often used to determine size a smaller object would be further from the sensor and would generate a smaller output than a larger object.) 7. Next we will set up the discrete output for this application. We will set up a Switching Window where the output is ON when the sensor detects a target between two set points and OFF when there is not a target detected between the two set points. Press SET and simultaneously for 3 seconds to begin the Teach process. (The green LED Power/Teach-In will begin blinking). 28 of 33