PROCESS CONTROL LAB. Lab In charge COURSE OBJECTIVES

Transcription

1 PROCESS CONTROL LAB COURSE OBJECTIVES 1. To control temperature, pressure, flow, level using PC with the help of different control modes. 2. To verify the operation of control valves. 3. To verify the operation of I/P & P/I converters. 4. To control the speed of DC motor. 5. To obtain the time domain specification for a second order system using PID controller. COURSE OUTCOMES 1. Able to verify operation of temperature, level, flow, pressure transmitter. 2. Able to control the flow rate in the range of 0 to 1000 LPH using PI controller. 3. Able to control the level in the range of 0-25 cm using PID controller. 4. Able to control the pressure in the range of 0 to 100 psi using PID controller. 5. Able to control the temperature in the range of 50 c to 500 c using ON/OFF controller. 6. Able to verify the operation of I/P & P/I converters. 7. Able to verify the operation of Quick opening and linear control valves. 8. Able to control the speed of a dc motor with help of various control modes. 9. Able to simulate a second order process and obtain the time domain specifications. Lab In charge HOD Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

2 PRESSURE TRANSMITTER EXPT. NO : 1(a) DATE : Aim: To perform an experiment to obtain the characteristic of pressure transmitter in the range of 0-75 Pounds per Square Inch(psi).. Tools and Testing Equipment Required: Work bench with DC Ammeter (0-30mA) Patch cords IBM PC Process control software Theory: The pressure transmitter (Strain Gauge based) senses the pressure from process vessel and converts it into proportionate standard electric signal (current (4-20mA)). The transmitter is calibrated for a maximum pressure of 100 psi. Principle of operation of Strain Gauge: Strain gauge (SG) is one of the most popular types of transducer. It has got a wide range of applications. It can be used for measurement of force, torque, pressure, acceleration and many other parameters. The basic principle of operation of a strain gage is simple: when stress is applied to a thin metallic wire, its dimension changes, thus changing the resistance of the wire. The change in resistance is converted into 4-20mA signal using conditioning. The 4-20mA signal is related to input pressure (psi) applied to SG. Procedure: 1. Make the circuit connections as shown in the figure VPPA-401 EXP. 2. Ensure that the VPCS cable is connected to process Analyzer from PC. 3. Switch on the mains supply. 4. Keep Hand Valve HV1 in open position and HV2 in closed position. 5. Supply pneumatic signal to the process station and ensure that PR1 (Pressure Regulator) is adjusted for an output line pressure of 20 psi and PR2 with 100psi. 6. Select control option and select manual mode and enter controller output as 100% Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

3 7. Use the ammeter reading (Digital Panel Meter-DPM) for transmitter output measurement. If you want to use any external ammeter connect it in serie with pressure Transmetter instead of DPM. 8. Gradually increase the process pressure in vessel upto 75 psi and record both pressure and corresponding DPM readings. Observations: Sl. No. Process pressure (Psi) Transmitter output (ma) Graph: Plot a graph with process pressure (psi) on x-axis and Digital Panel Meter DPM (ma) reading on y-axis. Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

4 Viva-Voce: 1. What is the principle of the transmitter in this experiment? 2. Why we will perform pressure transmitter experiment? 3. Define Process? 4. What are the main elements in process control loop system? 5. What is meant by disturbance element? 6. What is CV and MV? 7. What is the type of control valve used here? 8. What is the range of pressure used for FCE? 9. Difference between open loop system and closed loop system? 10. What are applications of Strain Gauge? 11. What are the different types of pressure sensors? 12. What are the different types of pressure sensing technologies? 13. What is meant by Absolute pressure? 14. Which instrument is used for pressure measurement? 15. What is meant by dynamic pressure? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

5 PRESSURE CONTROL EXPT. NO : 1(b) DATE : Aim: To study the action of following control modes for a pressure process using process control software 1. On-Off control 2. proportional control (P) 3. Proportional plus Integral control (PI) 4. Proportional plus Derivative control (PD) 5. PID control Tools and Testing Equipment Required: Work bench or process station Patch cords IBM PC Process control software Theory: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

6 ON-OFF control: ON-OFF control also referred as Two-position control and Open and close control in which the manipulated variable is quickly changed to either maximum or minimum value depending upon whether the controlled variable is greater than or less than set-point. If the controlled variable is below set-point the controller output is 100% and if the controlled variable is more than set-point the controller output is 0% considering zero differential gap. If differential gap is introduced, then the controller output is generated only when the controlled variable crosses above or below differential gap. Differential gap is defined as A small range of values through which the controlled variable must pass in order to move the FCE to both its extreme positions. This type of control applied to a process results in continuous oscillation of controlled variable and it never reaches steady value. Proportional control: To overcome the above problem Proportional control is used which is also called Throttling or Gradual or Modulating control action. This is defined as controlled action in which there is a continuous linear relation between value of controlled variable and position of the final control element with in proportional band. (y y 0 ) = Kp (x x 0 ) Where, (y y 0 ) is the change in valve position for a change in controlled variable (x x 0 ) form set-point and Kp is proportional gain. Tuning parameters are; 1. Proportional Band 2. Proportional Gain (Kp) 3. Time delay Proportional Band(PB): The percentage deviation in measured variable corresponding to 100% deviation in FCE. PB(%) =100 / [Kp(%)] The disadvantage of this mode is sustained deviation from set-point which is called Offset. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

7 Proportional plus Integral control (PI): Integra control or reset control combined with proportional control gives a controller action which always acts to maintain the controlled variable at set-point. The proportional control mode provides stabilizing influence while integral mode will help to overcome Offset. Integral controller provides corrective action as long as there is deviation in controlled variable form set-point. Integral control has a phase lag of 90º over proportional control and this lagging feature will result in slow response. The combination is most popular in applications of flow and pressure controls. Proportional plus Derivative control (PD): Derivative control or Rate control combined with proportional control provides a good control on processes having lags, since lags are compensated by anticipatory nature of derivative control or it provides the boost necessary to counteract the time delay associated. This is due to the fact that derivative control leads the proportional control by 90º. Hence this control is used on most multi-capacity process applications. Where the process lag is short, this combination could not be used. This controller combination does not eliminate Offset after sustained load disturbance because of narrow proportional band. This control properly tuned can act to prevent controlled variable from deviating excessively and reduces the time required to stabilize. Proportional plus Integral plus Derivative control (PID) When all the three control effects are combined together, we obtain the benefits of each control action and moreover the effect duplicates the action of a good human operator. Three mode controller contains stability of proportional control and ability to eliminate Offset because of reset control and ability to provide an immediate correction (anticipatory control) for a disturbance because of rate control. Procedure: 1. Make the circuit as shown in the connection diagram. 2. Ensure that the VPCS cable is connected between PC and Analyser. 3. Connect the air terminations AT3 TO AT4. 4. Adjust PR2 to obtain 100 PSI output for pressure vessel and PR1 to 20 PSI which is input to I/P converter. 5. Keep HV1 in fully open position and HV2 also slightly in open position. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

8 6. Invoke process control software on the PC and select any of the control action by using Control menu. 7. Select ON-Off control mode 8. Set the desired values of Setpoint and Differential gap by using settings/parameters in Menu 9. View the response by changing set-point and differential gap. 10. Also by varying HV2 positions (pressure in the vessel) see the process response. 11. Change the control mode to Proportional and observe the response. 12. Also change control modes to PI, PD and PID and observe the responses. Also observe responses by change of settings. Observations: Tabulate the values of Process Variable (Controlled variable) for specific periods of time for PID control mode. Tabular Column: Time(sec) PV (psi) CP (%) Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

9 Result: Viva-Voce: 1. Define Process? 2. Difference between open loop system and closed loop system? 3. What is the use of Data Acquisition and Control board used here? 4. What are the advantages and disadvantages of different control modes? 5. What are applications of Strain Gauge? 6. What is the difference between pressure transmitter experiment and pressure control experiment? 7. Which type of converter is used here? 8. Which control mode is mostly used? 9. Which software is used to control the pressure process? 10. Explain about piezoresistive strain gauge? 11. What is piezoelectric effect? 12. What are the applications of pressure sensors? 13. What are the different pressure units? 14. What is meant by static pressure? 15. What is meant by differential pressure? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

10 Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

11 TEMPERATURE TRANSMITTER EXPT. NO : 9(a) DATE : a) Aim: To perform an experiment to plot the characteristic of Temperature transmitter in the given range. Tools and Testing Equipment Required: Work bench with DC Ammeter (0-30mA) Patch cords IBM PC Process control software Theory: K-type thermocouple is used here to sense the temperature in the chamber,thermocouple converts Temperature into electrical signal which is standardized to 4-20mA and displayed on DPM. Principle of Thermocouple: A thermocouple is a sensor for measuring temperature. It consists of two dissimilar materials, joined together at one end. When the junction of the two materials is heated or cooled a voltage is produced that can be correlated back to the temperature. Procedure: 1. Plug in the mains 3-pin socket. 2. Switch ON the mains. 3. Make the connections as shown in the diagram. 4. Put the heater supply in ON position. 5. Select control option and select manual mode and enter controller output as 100% 6. Note the current readings which are output of transmitter and temperature readings from the front panel. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

12 Observations: S.No. Temperature (ºC) Transmitter current (ma) Graph: respectively. Plot a graph between temperature and transmitter output on x-axis and y-axis Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

13 Viva-Voce: 1. What are various temperature Sensors? 2. Define Process? 3. Define set point? 4. What is the principle of Thermocouple? 5. What are various types of Thermocouple? 6. What is CV and MV?. 7. What are CV and MV elements in this experiment? 8. What is the disturbance element in this experiment? 9. What is the FCE in this experiment? 10. What is meant by seebeck effect? 11. What are the applications of thermocouple? 12. what is meant by thermistor? 13. Difference between thermistor and RTD? 14. What is the relation between resistance and temperature? 15. What are different units of temperature? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

14 TEMPERATURE CONTROL EXPT. NO : 9(b) DATE : b)aim: To study the action of temperature process using, 1. On-Off control 2. proportional control 3. Proportional Integral control 4. Proportional Derivative control 5. PID control and to obtain the characteristics for different control modes. Tools and Testing Equipment Required: Work bench or process station Patch cords IBM PC Process control software Theory: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

15 Initially SCR unit is triggered ON which in turn switches the heater ON. Chamber gets heated up and temperature is sensed by thermocouple. Transmitter output is connected to PC through DA & C Board. Here PC acts as controller. When there is change in temperature from set-point control signals are generated depending on control mode which drives the SCR unit, in turn it controls the heater. On-Off control: ON-Off control also referred as Two-position control and Open and close control in which the manipulated variable is quickly changed to either maximum or minimum value depending upon whether the controlled variable is greater than or less than set-point. If the controlled variable is below set-point the controller output is 100% and if the controlled variable is more than set-point the controller output is 0% considering 0 differential gap. If differential gap is introduced, then the controller output is generated only when the controlled variable crosses above or below differential gap. Differential gap is defined as A small range of values through which the controlied variable must pass in order to move the FCE to both its extreme positions. Here in this experiment the number of degrees of temperature change necessary to go from ON to OFF or vice-versa of FCE This type of control applied to a process results in continuous oscillation of controlled variable and it never reaches steady value. Proportional control: To overcome the above problem Proportional control is used which is also called Throttling or Gradual or Modulating control action. This is defined as control action in which there is a continuous linear relation between value of controlled variable and position of the final control element with in proportional band. (y y 0 ) = Kp (x x 0 ) Where, (y y 0 ) is the change in valve position for a change in controlled variable (x x 0 ) from set-point and Kp is proportional gain. Tuning parameters are; Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

16 1. Proportional Band 2. Proportional Gain 3. Time delay Proportional Band: The percentage deviation in measured variable corresponding to 100% deviation in FCE. The disadvantage of this mode is sustained deviation from set-point which is called OFFSET. Proportional Integral control: Integra control or reset control combined with proportional control gives a controller action which always acts to maintain the controlled variable at set-point. The proportional control mode provides stabilizing influence while integral mode will help to overcome Offset. Integral controller provides corrective action as long as there is deviation in controlled variable form set-point. Integral control has a phase lag of 90º over proportional control and this lagging feature will result in slow response. The combination is most popular on applications of flow and pressure controls. Proportional Derivative control: Derivative control or Rate control combined with Proportional Control provides a good control on processes having lags, since lags are compensated by anticipatory nature of derivative control or it provides the boost necessary to counter act the time delay associated. This is due to the fact that derivative control leads the proportional control by 90º. Hence this control is used on most multicapacity process applications. Where the process lag is short, this combination could not be used. This controller combination does not eliminate Offset after sustained load disturbance because of narrow proportional band. This control properly tuned can act to prevent controlled variable from deviating excessively and reduces the time required to stabilize. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

17 T d = Derivative Time Proportional Integral Derivative control: When all the three control effects are combined together, we obtain the benefits of each control action and moreover the effect duplicates the action of a good human operator. Three mode controller contains stability of proportional control and ability to eliminate Offset because of reset control and ability to provide an immediate correction (anticipatory control) for a disturbance because of rate control. Procedure: 1. Make the connections as shown in the diagram. 2. Ensure that the VPCS cable is connected between PC and Analyzer. 3. Put the heater supply in ON position. 4. Invoke process control software on the PC and press any of the control action by using Control menu. 5. Place the control mode in On-Off mode. 6. In settings / parameters menu set set-point & Differential gap. Observe the response. 7. View the response by changing set-point and differential gap. 8. Using the Blower knob, vary the air flow and observe the response. 9. Change the control mode to Proportional and observe the response. 10. Also change control modes to PI, PD and PID observe the responses. Also observe responses by change of settings. Observations: Tabulate the values of Process Variable (Controlled variable) for specific periods of time for ON-OFF control mode.. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

18 Tabular Column: Time(sec) PV( 0 C) CP(%) Result: Viva-Voce: 1. What is the use of Data Acquisition and Control board used here? 2. What are the advantages and disadvantages of different control modes? 3. Which type of control mode is used in this experiment? 4. Why we use mostly ON-OFF control mode? 5. Explain about RTD? 6. What are the limitations of RTD? 7. What are the different materials used in RTD? 8. What are the different types of temperature sensors? 9. What are the mechanical types of temperature sensors? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

19 10. What are the electrical types of temperature sensors? 11. What are the examples of contact temperature sensors? 12. What are the examples of Noncontact temperature sensors? 13. What are the laws of thermocouples? 14. Explain about pyrometers? 15. What is meant by temperature regulators? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

20 FLOW TRANSMITTER EXPT. NO : 2(a) DATE : a)aim: To perform an experiment to plot the characteristic of Flow transmitter (Differential Pressure Transmitter-DPT) in the range of LPH. Tools and Testing Equipment Required: Work bench with DC Ammeter (0-30mA) Patch cords IBM PC Process control software Theory: The flow transmitter used here is DPT. It comes under Head type flow meter, where an Orifice is placed in the pipe line. Change in Flow causes change in differential pressure across orifice, which is picked up and converted into electric signal (current) and standardized to 4-20mA. Procedure: 1. Make the connections as per circuit diagram. 2. Make the pneumatic connections AT3-AT4 and AT1-AT2. 3. Ensure that the VPCS cable is connected between PC and Analyser. 4. See that HV1 & HV3 are fully opened, HV4 & HV5 are fully closed and HV2 is partially opened. 5. Adjust the air supply output of Pressure regulator to 20PSI which acts as input to I/P converter. 6. Switch ON the mains supply of the process. Invoke process control S/W on IBM PC. Select Manual Mode and enter a controller output of 100% Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

21 7. Set the flow rate to 0LPH by closing HV1and note the corresponding transmitter output current reading. 8. Increase the flow rate using HV1 to 50LPH and note the corresponding transmitter output current reading. 9. Gradually increase the flow rate in steps of 50 LPH upto 500 LPH and note down the corresponding transmitter output. Observations: S.No Flow (LPH) Transmitter output (ma) Graph: Plot a graph between flow and transmitter output on x-axis and y-axis respectively. Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

22 Viva-Voce: 1. What are various types of Mechanical and Electrical Type of Flow sensors? 2. What are the advantage and dis-advantage of Orifice plate? 3. What is the principle of the transmitter? 4. How can you measure and control Flow? 5. Explain about Rotameter? 6. Difference between closed loop system and open loop system? 7. What type of control valve is used in this experiment? 8. Define LPH? 9. Which type of converter is used in this experiment? 10. What are CV and MV elements in this experiment? 11. What is process tank and reservoir tank? 12. What is the FCE in this experiment? 13. Where we use ADC? 14. What is Doppler effect? 15. What are the units of measurement of flow? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

23 FLOW CONTROL EXPT. NO : 2(b) DATE : b) Aim: To study the action of Flow process using, 1. On-Off control 2. proportional control 3. Proportional Integral control 4. Proportional Derivative control 5. PID control And to obtain the characteristics for different control modes. Tools and Testing Equipment Required: Work bench or process station Patch cords IBM PC Process control software Theory: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

24 On-Off control: ON-Off control also referred as Two-position control and Open and close control in which the manipulated variable is quickly changed to either maximum or minimum value depending upon whether the controlled variable is greater than or less than set-point. If the controlled variable is below set-point the controller output is 100% and if the controlled variable is more than set-point the controller output is 0% considering 0 differential gap. If differential gap is introduced, then the controller output is generated only when the controlled variable crosses above or below differential gap. Differential gap is defined as A small range of values through which the controlied variable must pass in order to move the FCE to both its extreme positions. Here in this experiment the number of LPH change necessary to go from On to OFF or vice-versa of FCE This type of control applied to a process results in continuous oscillation of controlled variable and it never reaches steady value. Proportional control: To overcome the above problem Proportional control is used which is also called Throttling or Gradual or Modulating control action. This is defined as controlled action in which there is a continuous linear relation between value of controlled variable and position of the final control element with in proportional band. (y y 0 ) = Kp (x x 0 ) Where, (y y 0 ) is the change in valve position for a change in controlled variable (x x 0 ) from set-point and Up is proportional gain. Tuning parameters are; 1. Proportional Band 2. Proportional Gain 3. Time delay Proportional Band: The percentage deviation in measured variable corresponding to 100% deviation in FCE. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

25 The disadvantage of this mode is sustained deviation from set-point which is called OFFSET. Proportional Integral control: Integra control or reset control combined with proportional control gives a controller action which always acts to maintain the controlled variable at set-point. The proportional control mode provides stabilizing influence while integral mode will help to overcome Offset. Integral controller provides corrective action as long as there is deviation in controlled variable form set-point. Integral control has a phase lag of 90º over proportional control and this lagging feature will result in slow response. The combination is most popular on applications of flow and pressure controls. Proportional Derivative control: Derivative control or Rate control combined with Proportional control provides a good control on processes having lags, since lags are compensated by anticipatory nature of derivative control or it provides the necessary boostto counter act the time delay associated. This is due to the fact that derivative control leads the proportional control by 90º. Hence this control is used on most multicapacity process applications. Where the process lag is short, this combination could not be used. This controller combination does not eliminate Offset after sustained load disturbance because of narrow proportional band. This control properly tuned can act to prevent controlled variable from deviating excessively and reduces the time required to stabilize. (y-yo) = T d dx/dt T d = Derivative time Proportional Integral Derivative control: When all the three control effects are combined together, we obtain the benefits of each control action and moreover the effect duplicates the action of a good human operator. Three mode controller contains stability of proportional control and ability to eliminate Offset Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

26 because of reset control and ability to provide an immediate correction (anticipatory control) for a disturbance because of rate control. Procedure: 1. Make the connections as per circuit diagram. 2. Make the pneumatic connections AT3-AT4 and AT1-AT2. 3. Ensure that the VPCS cable is connected between PC and Analyser. 4. See that HV1 & HV3 are fully opened, HV4 & HV5 are fully closed and HV2 is partially opened. 5. Adjust the air supply output of Pressure regulator to 20PSI which acts as input to I/P converter. 6. Switch ON the mains supply of the process. 7. Invoke process control software on the PC and press any of the control action by using Control menu. 8. Place the control mode in On-Off mode. 9. In settings / parameters menu set set-point & Differential gap. Observe the response. 10. View the response by changing set-point and differential gap. 16. Change the control mode to Proportional and observe the response. 17. Also change control modes to PI, PD and PID observe the responses. Also observe responses by change of settings. Observations: Tabulate the values of Process Variable (Controlled variable) for specific periods of time for PI control mode.. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

27 Tabular Column: Time(sec) PV(LPH) CP(%) Result: Viva-Voce: 1. What is the use of Data Acquisition and Control board used here? 2. What are the advantages and disadvantages of different control modes? 3. Define differential gap? 4. ON-OFF control valve is also called as ? 5. What are the tuning parameters? 6. What is the range of pressure? 7. What is meant by sequential control system? 8. Rotameter is also called as ? 9. What are the different mechanical type flow meters? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

28 10. What are the different pressure type flow meters? 11. Optical flow meter is used for the measurement of ? 12. Define rate of fluid flow? 13. What are the types of ultrasonic type flow meters? 14. What are the applications of flow meter? 15. Where we use mass flow sensors? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

29 LEVEL TRANSMITTER EXPT. NO : 3(a) DATE : a)aim: To perform an experiment to plot the characteristic of level transmitter (capacitive) in the range of 0-25 cm. Tools and Testing Equipment Required: Work bench with DC Ammeter (0-30mA) Patch cords IBM PC Process control software Theory: The level sensing element is a metal probe which is inserted vertically into the medium from the top of the tank into the liquid. If tank is conductive it is used as ground reference and in insulated tanks the probe is enclosed by a concentric electrode to sense capacitance change. When the tank is empty, the probe and inner walls of the tank are separated by air. As level increases water fills up capacitance between insulated probe and tank increases. The change in capacitance is sensed and converted into current signal by bridge circuit and standardized at 4-20mA for transmission. Procedure: 1. Make the circuit connections as shown in the figure. 2. Connect the pneumatic lines AT1-AT2 & AT3-AT4 respectively. 3. Ensure that VPCS cable is connected between PC and Analyser. 4. Set the air pressure to 20psi. 5. Switch ON the mains supply. 6. Switch On pump1. 7. Close the process tank outlet valve HV2 connected to the reservoir. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

30 8. Switch ON the mains supply of the process. Invoke process control S/W on IBM PC. Select Manual Mode and enter a controller output of 100% 9. Fill the process tank with water upto a level of say 30cm. 10. Switch OFF the pump. 11. Gradually decrease the water level in the process tank by operating the outlet valve in steps of 5cm and record the corresponding transmitter output current readings. Observations: S.No Level (cm) Transmitter output (ma) Graph: Plot a graph between Level and transmitter output on x-axis and y-axis respectively. Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

31 Viva-Voce: 1. What are various Mechanical and Electrical Type of Level Sensors? 2. What is the principle of the transmitter? 3. What are the applications of Capacitance type sensors? 4. How can you control and measure the Level of the Liquid? 5. Define MV and CV? 6. Define interacting and non interacting process? 7. What is the FCE in this experiment? 8. Which type of valve is used in this experiment? 9. Which type of converter is used to change the valve position? 10. How we measure flow rate? 11. Which type of valve is used in this experiment? 12. Explain about Rotameter? 13. Define Time delay? 14. What is level measurement? 15. What are the different liquid level measurement techniques? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

32 LEVEL CONTROL EXPT. NO : 3(b) DATE : b)aim: To study the action of Level process using, 1. On-Off control 2. proportional control 3. Proportional Integral control 4. Proportional Derivative control 5. PID control and to obtain the characteristics for different control modes. Tools and Testing Equipment Required: Work bench or process station Patch cards IBM PC Process control software Theory: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

33 On-Off control: ON-Off control also referred as Two-position control and Open and close control in which the manipulated variable is quickly changed to either maximum or minimum value depending upon whether the controlled variable is greater than or less than set-point. If the controlled variable is below set-point the controller output is 100% and if the controlled variable is more than set-point the controller output is 0% considering 0 differential gap. If differential gap is introduced, then the controller output is generated only when the controlled variable crosses above or below differential gap. Differential gap is defined as A small range of values through which the controlled variable must pass in order to move the FCE to both its extreme positions. Here in this experiment the number of centimeters of level change necessary to go from ON to OFF or vice-versa of FCE This type of control applied to a process results in continuous oscillation of controlled variable and it never reaches steady value. Proportional control: To overcome the above problem Proportional control is used which is also called Throttling or Gradual or Modulating control action. This is defined as controlled action in which there is a continuous linear relation between value of controlled variable and position of the final control element with in proportional band. (y y 0 ) = Kp (x x 0 ) Where, (y y 0 ) is the change in valve position for a change in controlled variable (x x 0 ) form set-point and Kp is proportional gain. Tuning parameters are; 1. Proportional Band 2. Proportional Gain 3. Time delay Proportional Band: The percentage deviation in measured variable corresponding to 100% deviation in FCE. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

34 The disadvantage of this mode is sustained deviation from set-point which is called Offset. Proportional Integral control: Integra control or reset control combined with proportional control gives a controller action which always acts to maintain the controlled variable at set-point. The proportional control mode provides stabilizing influence while integral mode will help to overcome Offset. Integral controller provides corrective action as long as there is deviation in controlled variable form set-point. Integral control has a phase lag of 90º over proportional control and this lagging feature will result in slow response. The combination is most popular on applications of flow and pressure controls. Proportional Derivative control: Derivative control or Rate control combined with proportional provides a good control on processes having lags, since lags are compensated by anticipatory nature of derivative control or it provides the boost necessary to counter act the time delay associated. This is due to the fact that derivative control leads the proportional control by 90º. Hence this control is used on most multicapacity process applications. Where the process lag is short, this combination could not be used. This controller combination does not eliminate Offset after sustained load disturbance because of narrow proportional band. This control properly tuned can act to prevent controlled variable from deviating excessively and reduces the time required to stabilize. T d = derivative time Proportional Integral Derivative control: When all the three control effects are combined together, we obtain the benefits of each control action and moreover the effect duplicates the action of a good human operator. Three mode controller contains stability of proportional control and ability to eliminate Offset because of reset control and ability to provide an immediate correction (anticipatory control) for a disturbance because of rate control. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

35 Procedure: 1. Make the connections as per circuit diagram. 2. Connect the pneumatic paths AT3-AT4 & AT1-AT2. 3. Ensure that VPCS cable is connected between PC and Analyser. 4. Set the pressure to 20psi using regulator which forms input to I/P convertor. 5. Position the Hand valve HV1 fully open, HV2 partially open and HV3 fully open. 6. Switch ON the pump1 and select the desired speed by varying the variable speed control knob. 7. Invoke process control software on the PC and press any of the control action by using Control menu. 8. Place the control mode in On-Off mode. 9. In settings / parameters menu set set-point & Differential gap. Observe the response. 10. View the response by changing set-point and differential gap. 16. Change the control mode to Proportional and observe the response. 17. Also change control modes to PI, PD and PID observe the responses. Also observe responses by change of settings. Observations: Tabulate the values of Process Variable (Controlled variable) for specific periods of time for PID control mode Time(sec) PV(cm) CP(%) Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

36 Result: Viva-Voce: 1. What is the use of Data Acquisition and Control board used here? 2. What are the advantages and disadvantages of different control modes? 3. Which software is used to control the level? 4. What are the parameters we have to consider before starting the control experiment? 5. How we measure the liquid level using ultrasonic level measurement? 6. What are the types of ultrasonic level sensors? 7. What are the different methods for level detection of liquids? 8. For non-contact level sensing we use level sensors? 9. What are the different continuous level measurements of liquids? 10. What are the different tuning parameters? 11. P-control is also called as ? 12. What is the main draw back in P-control? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

37 Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

38 CONTROL VALVE CHARACTERSTICS EXPT. NO : 4 DATE : a)aim: To perform an experiment on control valve-1 Flow-Lift characteristics. and to identify the type of valve from Apparatus: Control valve-1 Pump Rotameter Air filter regulator Pressure gauge Theory: The relationship between flow through control valve and valve stem travel is known as the Flow Characteristic of the Control Valve.In most industrial process control systems control valve is the final control element. It is used to regulate flow of fluids (air, water, gas, steam etc.,). Two types of valves are available: 1. single seat Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

39 2. Double seat With single seat valve, the position of stem depends on both the unbalanced forces on plug from the pressure drop across the valve and the force produced by the motor. The effect of valve pressure drop can be minimized by using either a more powerful motor or valve positioner. The advantages of using double seats are that the pressure drop forces on the plugs almost cancel, and also flow capacity is up to 30% greater than for single seat valve of same size. Also this valve cannot be tight close and would not be used where positive shut off is essential. Control valve components: 1. Actuator 2. Valve Actuator components: Flexible diaphragm Spring Plate, stem and lock nut Housing Valve components: Body Plug Stem Pressure tight connection Both steady state and dynamic characteristics of the valve should be considered in the design of Process control system. The steady state behavior depends mainly on size and shape of plug and on pressure drop across the valve. The actuator design has a slight effect on steady state position, since a powerful actuator or a positioner can reduce the hysterisis caused by stem friction. The dynamic response of the valve depends primarily on the actuator and the length of the transmission line from the control valve. The inertia of the moving stem and plug is usually negligible. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

40 The flow through a sliding stem control valve usually follows the Orifice equation for uncompressible fluids, Control is achieved by moving the stem to vary the area for flow. The gain of the valve or change in flow for given change in stem position depends on change in area with stem position and also on change in pressure drop with flow, hence this pressure is maintained constant through out the experiment. Procedure: 1. Set the supply pressure to 15psi using air pressure regulator. 2. Open the Hand valve HV2 and partially open HV1. 3. Open HV3, HV5 & close HV4, HV6 for selection of control valve Switch ON the pump. 5. Adjust the variable speed so that the Rotameter reading shows 1000 LPH. 6. Note the across pressure developed in the gauge. 7. Set the pressure at 15 psi to the control valve. 8. Vary the hand valve HV1, adjust the across pressure to previous value on gauge. 9. Note down the readings of stem position and Rotameter by varying supply pressure from 15psi to 3psi, at constant across pressure Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

41 Observations: S. No Input pressure (psi) Stem position (%) Flow (LPH) Graph: Plot a graph with lift (stem position) and Flow on x-axis and y-axis respectively. Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

42 b)aim: To perform an experiment on control valve-2 and to identify the type of valve from Flow-Lift characteristics. Apparatus: Control valve-2 Pump Rotameter Air filter regulator Pressure gauge Procedure: 1. Set the supply pressure to 15psi using air pressure regulator. 2. Open the Hand valve HV2 and partially open HV1. 3. Close HV3, HV5 & open HV4, HV6 for selection of control valve Switch ON the pump. 5. Adjust the variable speed so that the rotameter reading shows 1000 LPH. 6. Note the across pressure developed in the gauge. 7. Set the pressure at 15 psi to the control valve. 8. Vary the hand valve HV1, adjust the across pressure to previous value on gauge. 9. Note down the readings of stem position and rotameter by varying supply pressure from 15psi to 3psi, at constant across pressure. Observations: S. No Input pressure (psi) Stem position (%) Flow (LPH) Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

43 Graph: Plot a graph with lift (stem position) and Flow on x-axis and y-axis respectively. Model Graph: Result: Viva-voce: 1. What are various types of control valve characterstics? 2. How to change the characteristic of the valve? 3. What are Types of plugs? 4. What is the operational difference between air-to-open and air-to-close valves? 5. How to change the initial position of valve? 6. In PCI lab, Which type of Control valve is used in LPA,FPA & PPA? 7. Define the term rangeability? 8. Explain the difference between ideal and effective characteristics? 9. Explain the basic principle of operation of a pneumatically actuated control valve? 10. Explain the constructions and relative advantages and disadvantages of single- seated and double-seated valves? 11. Classification of control valve is done based on? 12. Multi turn valve is also called as ? 13. Give examples of multi-turn valve? 14. Quarter-turn valve is also called as ? 15. Give examples of Quarter-turn valve? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

44 Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

45 I/P CONVERTOR EXPT. NO : 5 DATE : Aim: To perform an experiment to convert current to pressure in the range of 4-20mA and to plot the characteristic. Tools and Testing Equipment Required: Pressure gauge Current source Ammeter (DPM) I/P convertor Compressor Air pressure filter and regulator Theory: Flapper-Nozzle system (F/N) is used here for conversion of current to proportionate pressure as shown in the diagram. One end of the flapper is placed near the nozzle and the other end is placed near the current carrying coil. This coil is energized by current flowing through it, which forms input to the system. A pressure of 20Psi is given as supply to F/N system. When input current is increased, flapper moves towards the nozzle and leakage to atmosphere is reduced, increasing back pressure which forms the output of system. When current is reduced, the flapper moves far away from nozzle increasing leakage to atmosphere, reducing back pressure (output). Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

46 F/N system: Procedure: 1. Switch ON the compressor and Unit. 2. Ensure that the I/P converter connection is made. 3. Adjust the supply pressure to 20Psi using pressure regulator. 4. Adjust the input current to 4mA using the Potentiometer on front panel. 5. Note down the corresponding output pressure on pressure gauge. 6. Repeat the experiment by varying the input current upto 20mA in steps of 2mA. Observations: S.No Input current (ma) Output Pressure (Psi) Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

47 Graph: Plot a graph between Input current and output pressure on x-axis and y-axis respectively Model Graph Result: Viva-voce: 1. What is the transducer used in conversion of P/I. 2. How I/P conversion is made? 3. What is dummy gauge in bridge circuit? 4. How Pressure developed in flopper Nozzle Systems? 5. What are the applications of I/P and P/I converters? 6. Why we use strain gauge in P/I conversion? 7. What is current range we observe? 8. Why can t we observe values before 4MA and 3PSI? 9. Define PSI? 10. Give some examples where we use P/I and I/P converter? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

48 P/I CONVERTOR EXPT. NO : 6 DATE : Aim: To perform an experiment to convert pressure to current in the range of 3-15 Psi and to plot the characteristic. Tools and Testing Equipment Required: Pressure gauge Ammeter (DPM) P/I convertor Compressor Air pressure filter and regulator Theory: Transducer used here for conversion from P to I is strain gauge, which is a metal wire or strip and is attached to pressure sensing device such as diaphragm. When diaphragm gets deflected upon pressure application, the strain gauge is stretched or compressed by which its resistance changes depending on the magnitude of pressure. The governing equation is given by, Where, ρ is resistivity L length of strain gauge A is cross-sectional area Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

49 This change in resistance is measured by using a wheat stone bridge, comprising of one strain gauge and three standard resistors all having equal values or two strain gauges and two standard resistors or all 4 strain gauges. Under no pressure conditions the bridge is in balanced Condition. When pressure is applied, strain gauges resistance changes and hence bridge is unbalanced. Hence an unbalanced output current is produced which is a measure of input pressure. This current output is standardized and displayed as 4-20mA for an input pressure of 3-15psi in this experiment. Procedure: 1. Switch on the compressor and Unit. 2. Ensure the P/I converter connection. 3. Adjust the input pressure to 20Psi using pressure regulator. 4. Give the input pressure of 3psi to P/I converter using needle valve. 5. Note down the corresponding value of current on DPM. 6. Repeat the steps of 4 & 5 upto 15Psi in steps of 2Psi. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

50 Observations: S.No Input Pressure (Psi) Output current (ma) Graph: Plot a graph between Input pressure and output current on x-axis and y-axis respectively. Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

51 DC SERVO MOTOR CONTROL EXPT. NO : 7 a)aim: To study the error between actual speed and measuring speed of DATE DC SERVO : motor a) Aim: To study the error between actual speed and measuring speed of DC Servo motor with and without load in closed loop control. Tools and Testing Equipment: DC servo controller DC motor 12V, 1.5A, Max. speed 1500 rpm. Multimeter Patch cords Load (Permanent magnet) Theory: The objective is to control the speed of the motor using Proportional and Integral control. Disturbance can be given by load change or set-point change. The input to the system is setspeed or command speed given in terms of voltage using potentiometer on front panel. The output is speed of the motor which is measured using Optical Sensor and given as feed back to the control system. Depending upon the error and control mode, the controller generates the necessary control signals and regulates the speed of motor. Load disturbance is given using a permanent magnet onto a rotating metal plate fixed to rotor. As the plate rotates in magnetic field eddy current are generated. The field produced by eddy currents opposes the permanent magnet field and hence speed reduces. This is taken as load disturbance. The control system senses the reduction of speed and initiates necessary corrective action to increase the speed of motor to reach the set-speed. Block diagram for speed control SP error Controller FCE Speed Measurement (Transducer & transmitter) Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

52 Procedure: 1. Ensure power is OFF to the motor servo controller and pulse release switch is in OFF position. 2. Set the controller to proportional mode by grounding the Integral line. 3. Connect the motor to servo controller as shown in the diagram. 4. Set the speed reference voltage Vref to 3.35 volts and keep the proportional gain Kp at minimum. 5. Switch ON the power to the servo controller. 6. Switch ON the Pulse ON/OFF switch. 7. By adjusting the Kp, make the motor to run without any oscillations and Note down the following parameters. i. Vr the reference speed voltage(volts) ii. Va motor armature voltage(volts) iii. Error speed - (Na Ns) Revolution per Minute (rpm) iv. Ia motor armature current(a) v. Na Actual speed in Revolution per Minute (rpm) vi. Ns Set speed Revolution per Minute (rpm) 8. Vary the proportional gain Kp as given in table1 in steps and record the above quantities. 9. For table2, keep the p-gain constant at 5% and vary the load angle as shown in table and record the parameters. 10. Reduce the speed and switch OFF the power supply. 11. Calculate the errors using Na- Ns.. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

53 Observations: i. closed loop without load P control: S.No. P-Band Vr (V) Set speed Actual Ia (A) Va Error % Ns (rpm) speed (V) (Na Ns) Na (rpm) rpm ii. closed loop with load P control: S.No. P-Band % Vr (V) Set speed Ns (rpm) Load angle Ia (A) Va (V) Actual speed Na (rpm) Error (Na Ns) rpm Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

54 b)aim: To study the error between actual speed and measuring speed of DC SERVO motor using proportional-integral control with and without load in closed loop control. Tools and Testing Equipment: DC servo controller DC motor 12V, 1.5A, Max. speed 1500 rpm. Multimeter Patch cords Load (Permanent magnet) Theory: The block diagram of closed loop control system with PI control of D.C. Servo Motor System is shown in below Figure. The error signal E(s) is fed into two controllers, i.e. Proportional block and Integral block, called PI controller. The output of PI controller, U(s), is fed to D.C. Servo Motor System. The overall output of D.C. drive, may be speed or position, C(s) is feedback to reference input R(s). Error signal can be removed by increasing the value of Kp, Ki. Procedure: 1. Ensure power is OFF to the motor servo controller and pulse release switch is in OFF position. 2. Set the controller to proportional-integral mode. 3. Connect the motor to servo controller as shown in the diagram. 4. Establish the speed feedback loop using patch cord as shown in figure. 5. Set the speed reference voltage Vref to 3.35 volts and keep the proportional gain Kp at minimum. 6. Switch ON the power to the servo controller. 7. Switch ON the Pulse ON/OFF switch. 8. By adjusting the Kp make the motor to run without any oscillations and Note down the following parameters. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

55 a. V r the reference speed voltage(volts) b. Va motor armature voltage(volts) c. Error speed - (Na Ns) Revolution per Minute (rpm) d. Ia motor armature current(a) e. Na Actual speed in Revolution per Minute (rpm) f. Ns Set speed Revolution per Minute (rpm) 9. Keep the proportional gain Kp constant at 5% and vary the Integral time (Ti) as shown in table1 in steps and record the above quantities. 10. For table2, keep the p-gain constant at 5%, Ti at 1.0 and vary the load angle as shown in table and record the parameters. 11. Reduce the speed and switch OFF the power supply. 12. Calculate the errors using Na- Ns.. Observations: i. Closed loop without load PI control: S.No. P-gain % Vr (V) Set speed Ns (rpm) Integral time (Ti) sec Actual speed Na (rpm) Ia (A) Va (V) Error (Na Ns) rpm ii. Closed loop with load PI control: S.No. P- Vr Set speed Load Integral Ia Va Actual Error gain % (V) Ns (rpm) angle time(ti) sec (A) (V) speed Na (rpm) (Na Ns) rpm Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

56 Result: Viva-voce: 1. What are various types of speed sensors? 2. What are various non contact speed sensors? 3. Explain the basic building blocks of speed control system? 4. What is load disturbance? 5. How can you avoid load disturbance effect? 6. How we apply load angle? 7. Define Gain of power amplifier? 8. Define Proportional gain? 9. How to calculate error? 10. What is Integral time? 11. Where we use integral time? 12. For which type of control mode we use open loop system? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

57 Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

58 PROCESS CONTROL SIMULATOR EXPT. NO : 8 DATE : a)aim: To observe the time response of closed loop second order process using proportional control. Tools and Testing Equipment: Process control simulator Trainer CRO Probes Patch cords Theory: When the control signal applied to the process is proportional to deviation, the control is termed as proportional. The range of values that causes the controller output to cover its full range is called proportional band. Adjustment of %PB varies the gain of the controller. This experiment will examine the effects of changes in percentage of the PB and the response of the system to disturbances. Procedure: 1. Make the connections on the front panel of PCS-01 as shown in diagram. 2. Set the process fast / slow switch (SW4) in fast position. 3. Keep the set value potentiometer to ZERO. 4. Apply a square wave signal of 2V peak-to-peak at around 50Hz. 5. Alternatively display in the oscilloscope the set value disturbance point and measured value from the point PV. 6. Repeat all the above step with the change in %PB as shown in table. 7. As each step is applied, system responds as shown in the figure. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

59 Observations: S.No. %PB Peak over shoot Rise Peak time Settling Damping Mp (V) time(t r ) (t p ) sec time(t s ) ration(ξ) sec sec Conclusion: The system moves slowly towards the set value, overshoots, returns and after a few oscillations, settles so that the measured value is less than the set value. When it has settled there exists a considerable deviation As the %PB is reduced, i.e., the gain of the system is increased as Kp = 100% / %PB this steady state deviation is reduced and the system settles with its measured value much closer to set value. Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

60 b) Aim: To study the time response of closed loop second order process with P+I controller. Tools and Testing Equipment: Process control simulator Trainer CRO Probes Patch cords Theory: In an ideal system the measured value and the set value should be the same and under steady state condition the deviation should be zero. What is required is an alternative signal to be fed into the main amplifier of sufficient size to provide an output if a steady state deviation exists viz to reduce the Offset to zero. Such a signal can be provided by an integrator which gives a constantly increasing output for a steady value error. Such an arrangement is known as P+I controller and should reduce any steady state deviation to zero. Procedure: 1. Make the connections on the front panel of PCS-01 as shown in diagram. 2. Set the process fast / slow switch (SW4) and the controller fast / slow switch (SW3) in fast position. 3. Keep the set value pot at zero. 4. Apply a square wave of 2V peak to peak at around 50Hz. 5. Adjust the Proportional band control until the system settles with 2 to 3 overshoots. 6. Now connect the integral section as shown in fig. 7. Slowly reduce the integral action time until deviation falls to zero. 8. Monitor both the set value disturbance socket and PV socket. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

61 Observations: S.No. %PB Ti Peak over Rise Peak Settling Sec shoot (Mp) (V) time(t r ) sec time (t p ) sec time(t s ) sec Model Graph: Result: Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

62 c) Aim: To study the time response of P+I+D controller on a process. Tools and Testing Equipment: Process control simulator Trainer CRO Probes Patch cords Theory: Integral control improves the performance of the control system in some respects, i.e., reduces the steady state deviation, but has the disadvantage of slowing down the over all response time. If a system was required to follow a sudden change in set value this would give rise to a rapid change in deviation. Although this deviation change is rapid the system responds rather slowly, so if at this time the controller output could be boosted the speed of the system response should be improved. If the deviation was differentiated, i.e., rate of change measured, and a signal produced proportional to this and then added to the signals from the proportional and integrator sections, some improvement should result. Such an arrangement is known as three term controller or PID controller. Procedure: 1. Make the connections on the front panel of PCS-01 as shown in diagram. 2. Set the process fast / slow switch (SW4) and controller fast / slow switch (SW3) in fast position. 3. Apply a square wave of 2V peak to peak at around 50Hz. 4. Now patch I and I and adjust the integral time until steady state deviation is zero. 5. Now note down the number of overshoots before the system settles. 6. Now connect D and D and slowly increase the derivative time and note down the effect of this in the system response. Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

63 Observations: S.No. %PB Ti T D Peak over Rise Peak Settling sec sec shoot (Mp) (V) time(t r ) sec time (t p ) sec time(t s ) sec Result: Viva-voce: 1. What is transient response? 2. What is Steady state response? 3. What are various time domain specifications? 4. What are various standard test signals? 5. What is Proportional Band? 6. How to measure settling time For P control? 7. What are the different types of controllers? 8. What is meant by MIMO and SISO system? 9. Difference between feedback and feed-forward controllers? 10. Define dead time compensation? 11. Define inverse response compensation? 12. Examples for Discontinuous controller modes and Continuous controller modes? 13. In which type control mode offset error is observed and in which type it is eliminated? 14. What are the different composite control modes? 15. Define process lag and process lead? 16. Define Control lag? 17. Derivative Control action is also called as ? 18. If Kp is increases, PB will If Kp is increases, SSE will be What do you observe for Mp,Tr,Td,SSE w.r.t PI,PD and PID controller? Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram

64 Lakireddy Bali Reddy College of Engineering, L.B.Reddy Nagar, Mylavaram