OVEN INDUSTRIES, INC. OPERATING MANUAL MODEL 5C7-195 THERMOELECTRIC MODULE TEMPERATURE CONTROLLER
TABLE OF CONTENTS Page Features...1 Description...2 Block Diagram...2 Mechanical Package Drawing...3 RS232 Communications Connections...4 Sensor Wiring...4 TEC and Power Supply Wiring...5 Internal Power Supply Load Circuit Capability...5 Setup Screen with Factory Default Settings...7 Set-Up Instructions...8 Appendix A - Troubleshooting Communications Port...9 Appendix B - Calibration of INPUT1 & INPUT2...10 Appendix C - Datalogging...10 Appendix D - 5 Minutes to PID Tuning... 11 In no event shall Oven Industries, Inc. be liable for any damages whatsoever (including without limitation, damage for loss of business profits, business interruption, loss of business information, or any other pecuniary loss) arising out of the use or inability to use this Oven Industries, Inc. product, even if Oven Industries, Inc. has been advised of the possibility of such damages.
CAUTION: Always be careful around heaters and TE modules, their related heat sinks, or other parts of the thermal system. Do not come into contact with a hot or very cold surface. Use thermal fuses for additional protection. Do not leave an active thermal system unattended without taking all necessary safety precautions. Follow all safety requirements of your location and your thermal system. FEATURES INPUT VOLTAGE: 85 to 260VAC, 50/60 Hz INTERNAL POWER SUPPLY FOR VARIABLE DC OUTPUT VOLTAGES 3.5VDC TO 20VDC MAXIMUM OUTPUT CURRENT, H Bridge Operation (See figure 1) PROPORTIONAL CONTROL WITH AUTOMATIC RESET (PID) CONTROLLER OUTPUTS PULSE WIDTH MODULATED AT 2700Hz CONTROL SENSOR AND ALARM SENSOR LOAD CIRCUIT IS PC CONFIGURABLE FOR TE Module: Internal Power Supply (See Figure 1) Heat/Cool: Internal Power Supply (See Figure 2) Heat/Cool: 10 Amp External Power Supply ISOLATED RS232 COMMUNICATIONS PORT TEMPERATURE ADJUSTMENT AND RESOLUTION IS 0.1 C OPEN OR SHORT SENSOR PROTECTION DISABLES LOAD CIRCUIT CONTROL TEMPERATURE RANGE 40 C TO 150 C Temperature Sensor: GUI Select TS141-40 C TO 70 C TS91-20 C TO 85 C TS67-20 C TO 100 C TS104 0 C TO 150 C 1
General Description Model 5C7-195 is a bi-directional controller for Thermoelectric modules. It has an internal power supply and full H bridge capable of load currents up to 4 amperes. Model 5C7-195 may be used as a heat or cool only controller with resistive heaters or TE modules with load currents of up to 5 amperes. Model 5C7-195 may be used in conjunction with an external power supply as a heat only, or cool only controller with load currents up to 10 amps. The controller s internal power supply accepts the universal AC voltage range of 85VAC to 260VAC. Electrical isolation is maintained between the AC power input and the DC load circuits. The H bridge configuration of solid state MOSFET output devices allows for the bi-directional flow of current through the thermoelectric modules. The controller is PC programmable via an RS232 communications port for direct interface with a compatible PC. The RS232 communications interface has 1500 VAC isolation from all other electronic circuitry minimizing interference from noise or errant signals caused by common ground loops. The easily accessible communications link permits a variety of operational mode configurations. Field selectable parameters or data acquisition in a half duplex mode can be performed. This controller will accept a communications cable length in accordance with RS232 interface specifications. Once the desired set parameters are established the PC may be disconnected and the Model 5C7-195 becomes a stand alone controller. All parameters are retained in non-volatile memory. The controller has a digital display of control functions. The front panel controls may be used to adjust the set temperature, or to adjust the output voltage when the internal power supply is used, or to view the actual or alarm temperature. The user friendly, communications software requires no prior programming experience to establish operation. A command set is provided for qualified personnel to program a software interface and data log information. The controller is provided in a plastic case suitable for bench top use. Block Diagram AC Power Power Supply 24VDC Adjustable Voltage DC to DC Converter Control Sensor CONTROL Power Supply Select Internal/External External Power Supply Alarm Sensor RS232 Bandwidth Integral Reset Derivative Set Temperature Set Voltage Alarms Sensor Select Output Select Outputs H Bridge 4 AMPS Bi-Directional Heat Only Cool Only 5 AMPS Display Heat Only Cool Only 10 AMPS 2
MECHANICAL PACKAGE DRAWING 3
RS232 COMMUNICATIONS CONNECTIONS PC CONNECTION TABLE PC CONNECTOR PCFUNCTION* CONTROLLER 9 PIN PIN 2 25 PIN 3 RECEIVE (RX) TANSMIT(TX) PIN 3 2 TRANSMIT (TX) RECIEVE (RX) PIN 5 7 COMMON SHIELD 3 2 5 RX TX SHLD Check your PC manual to confirm pin assignments TX RX COMMON RS232 COMPUTER SENSOR WIRING When plugged in to the controller, the button on the sensor connector faces left. The connector snaps into place and the button must be depressed in order to unplug the connector. Sensor 4
Set Load Voltage in VDC 20 Figure 1 H Bridge BI-POLAR Internal Power Supply Load Circuit Capability 20 Figure 2 Uni-Directional UNI-POLAR Set Load Voltage in VDC 16 15 10 6 5 3.5 15 14 10 6 5 3.5 1 2 2.5 3 4 1 2 3 4 5 Load Circuit Connections The operating mode is selected via RS232 communication port and the GUI (Graphical User Interface) PC Software. The connected load must stay within the safe operating area defined in Figure 1 and 2. An external fast acting fuse shoud be used as additional load circuit protection. Model 5C7-195 may be operated in three different modes. H Bridge Internal Power Supply (Figure 1) Heat or Cool: Internal Power Supply (Figure 2) Heat or Cool: External Power Supply. An external power supply of 1vdc to 28vdc may be used with a maximum load current of 10 amps. 5
Load Circuit Connections (Cont d) Diagram 1 Connections when using the Internal Power Supply for H-Bridge, Bi-Directional (Bi-Polar) Control: Load Connections 4 amps max. See page 5, Figure 1 for the load circuit capability Diagram 2 Connections when using the Internal Power Supply for Uni-Directional (Uni-Polar) Control: Load Connections 5 amps max. See page 5, Figure 2 for the load circuit capability Diagram 3 Connections when using the External Power Supply for Uni-Directional (Uni-Polar) Control: Load & Power Supply Connections 6
Setup GUI Screen with Factory Set Defaults in Red COM 1 COM 2 COM 3 COM 4 COOL HEAT H-BRIDGE DISABLE HIGH ALARM LOW ALARM TS67-20 C to 100 C TS91-20 C to 85 C TS104 0 C to 150 C TS141-40 C to 70 C 7
SET UP INSTRUCTION 1. AC Power: Without a load (heater or TEC) connected to the controller, connect the controller to AC power using the AC line cord. Turn on the controller using the power switch at the back. The LED display will initially show the software version, such as re6, and then, if no control sensor is attached, it shows Err. 2. Attach the Communications Cable: Connect a communications cable from the controller to your PC (see page 5). The connector required for the back of the controller is a standard DB9 (DE9P) connector. 3. Launch the Setup Software: Note the execute command shown on the label of the software disk. Insert the disk into the PC and use this command to launch your controller s Setup program. The GUI (see facing page) will be on the PC screen. 4. Select the COMM Port: In the PC COMMUNICATIONS section, select the Comm Port and click INITIALIZE. Within a couple of seconds you should see values in the TUNING, CALIBRATE, and CONFIGURE sections. If the software fails to communicate with the controller see Appendix A, Troubleshooting the Communications Port. If you need to Exit the program you can use the Closer (the X button, top right) to exit, and then return to step 3. 5. Select the Sensor Type: The same type of sensor (TS67, TS91, TS104, TS141) is used for both the temperature control sensor and the alarm sensor. In the CALIBRATE section, select the Sensor Type you are using with this controller and then click the section s Send Box Values button. 6. Set the Load Voltage: In the TUNING section, enter the rated voltage of the load (heater or TE Module) as the SET SWITCH VOLTAGE (output voltage). Be sure the rated current is within the safe operating area of the power supply. When using the controller s internal power supply, refer to Figures 1 & 2 on page 7, Internal Power Supply Load Circuit Capability. 7. Set the Alarm: While in an alarm state, the output power to the load will be turned off. Use this feature as a precaution against excessively high temperatures: In the CONFIGURE section set the ALARM to High Alarm and click the section s Send Box Values button, and then in the TUNING section enter the high temperature value as the ALARM SETTING and click the section s Send Box Values button. Or, in a similar way, you can choose to use a Low Alarm, or you can choose to Disable the alarm feature. Choose to Disable the alarm if you are using only a control sensor and no alarm sensor. 8. Select the Heat/Cool Mode: In the CONFIGURE section select the appropriate HEAT/COOL mode. If using a heater, select Heat and click Send Box Values. If using a TE module your selection depends on how you are going to connect the load and power see page 7 and 8 for Load Circuit Connections. Select Heat or Cool for uni-directional control of the TE module, or select H-Bridge for bi-directional (bipolar) control, and then click Send Box Values. (With bi-directional control the controller will automatically use the TE module to heat or cool as needed.) 9. The Set Point Temperature: In the TUNING section enter the desired set point temperature as the FIXED SET TEMP and click Send Box Values. The temperature scale is Celsius ( C). Ambient room temperature of 70 F is about 25 C, and so, if you want to gain experience with the controller near ambient start with 25 as the FIXED SET TEMP. 10. Tune the PID Control: In the TUNING section use the PROPORTIONAL BANDWIDTH (P), INTEGRAL GAIN (I), and DERIVATIVE GAIN (D) to tune the PID control. You can start with 10 for the bandwidth, and 0 (zero) for the integral and derivative gain. Enter your PID values and click Send Box Values. Once you are familiar with the operation of the controller, you can use Appendix D, 5 Minutes to PID Tuning of the Temperature Controller. 11. Exit the Setup Program and then Turn Off the Controller: Use the File menu and Exit to exit the program, and use the power switch at the back of the controller to turn off the controller. 12. Connect the Load: Connect your load (heater or TE module) according to the appropriate Load Circuit Connections diagram on page 8. If you are using the controller s internal power supply, use Diagram 1 for H-Bridge (bi-directional) control, or use Diagram 2 for Heat only or Cool only control. If you are using an external power supply for your load, use Diagram 3. 13. Attach the Sensors: Place the control sensor into the heater or TE module thermal system at the desired control point. Connect the sensor to the controller. Do the same for the alarm sensor if you are using one. 8
14. Check all connections. 15. Turn the Controller On and it will Immediately Begin Controlling the Temperature: The control sensor s temperature will be indicated on the front panel display. By cycling the display using the front panel s DISPLAY SELECT button, and noting the LED indicators, you can view the Actual, Set, and Alarm Temperatures, or the Set Voltage. (If no alarm sensor is attached, the Alarm Temperature is displayed as Err.) By using the INCREASE and DECREASE buttons, you can adjust the Set and Alarm Temperatures, or the Set Voltage. 16. Launch the Setup Software: If you want to use the Setup program to change controller parameters or log data, launch the program according to the instructions for steps 3 and 4. If you want to datalog, or chart logged data, see Appendix C, Datalogging. To calibrate the sensors, see Appendix B, Calibration of INPUT1 & INPUT2. 17. Setup is Complete: It is a good idea to use safe temperature settings in order to become accustomed to your set up and to tuning the controller. APPENDIX A Troubleshooting the Communications Port Error Message Comm Port Timeout Cause No power to temperature controller Solution Supply power to the controller Comm Port Timeout Wrong comm port selected Check computer hardware settings and set to the cor rect comm port. Comm Port Timeout Incor rect wiring of the comm port to the computer Check for the cor rect wiring from the controller to the computer Comm Port Open Error No Comm Port available at this por t setting Check computer hardware setting and set to the cor rect comm port. 9
APPENDIX B Calibration of INPUT1 & INPUT 2 The Setup screen that is available on the PC provides two fields that can be used for single-point calibration of the sensors. IINPUT1 OFFSET and INPUT2 OFFSET allow the adjustment of the temperature reading so that it conforms more closely to an independent sensor (such as a calibration grade thermometer) that is believed to be more accurate than the sensor used with the controller. EXAMPLE The TS67 sensor attached to the controller reads 35 C, while another instrument reads 37 C. The TS67 is reading 2 C lower than the test instrument. The user wants to have these two temperatures in agreement. Assuming the two temperatures are measured correctly (with sensors properly positioned and compensation made for thermal system and ambient characteristics) then we need a way to Offset (calibrate) the TS67 sensor. This is accomplished by entering -2 into the INPUT1 OFFSET box. The controller will then move the sensed temperature, and therefore the control point, by -2 C, so that at 35 C the controller and the test instrument will be in agreement. The alarm sensor reading can be adjusted in a similar manner by using the INPUT2 OFFSET box. NOTE: This may not be correct over the entire adjustment span, because of sensor non-linearities and the difference in the thermal system over the operating temperature range. APPENDIX C Datalogging You can use a spreadsheet to log or even graph temperature data if you use the Setup program at the PC. When you use the SAMPLE ON/OFF button to turn sampling on, also enable the DATA LOG BOX. Run the controller over the time period desired and requested values will accumulate in the box. When desired time period expires, disable the DATA LOG BOX and turn off sampling. Right click on the DATA LOG BOX and click Select All in the context sensitive menu. Right click again and click on the Copy menu item. You can now paste the values into a spreadsheet. Click in a cell in the second column of a blank spreadsheet and press CTRL-V. Each column that was in the DATA LOG BOX will be pasted into a column of the spreadsheet. We pasted the values starting in the second column because in order to graph you may need to use the first column for time or for the number of a measurement. For example, if you had sampling set for once per second, put a sequence of numbers in the first column such as 0, 1, 2, etc. Now use the graphing software appropriate to your spreadsheet application to see the values graphed over time, with time being in seconds. 10
APPENDIX D APPLICATION NOTE 353 5 Minutes to PID Tuning of the Temperature Controller Tuning the temperature controller involves three variables which are accessed through the PC Setup program. (P)ropotional bandwidth (I)ntegral action (D)erivative rate The control algorithm sums the three values of these terms to determine the output power. P + I + D = % Power Applied Most applications work satisfactorily with only the P and I values used. Start the tuning process by setting the Integral and Derivative functions to zero. Proportional Bandwidth is defined as the temperature range around the setpoint where the controller modulates (proportions) the output power. In a heating application, if the temperature is above the proportional band, the controller output is OFF. If the temperature is below the proportional band, the controller output is ON. Each thermal system has its own time constants determined by the thermal mass of the components and the placement of the sensor relative to the load. To tune the system the bandwidth must be wide enough that the controller can sense a change and react to it before the temperature drifts outside the bandwidth. If the bandwidth is too small the output will oscillate above and below the setpoint, never settling into control. The bandwidth range is 1 to 100. The units are shipped with a default setting of 20. Assuming the controller is configured for your requirements, start the tuning process by applying power with the default settings and observing the system s response. If the system comes into the proportional band and maintains a steady temperature near setpoint, without over shoot, the bandwidth setting is satisfactory or too large. Reduce the bandwidth setting until the system just begins to oscillate. At this point, the bandwidth is too small. Note the bandwidth setting that just caused the system to oscillate, record the period of oscillation for use in determining the Integral Reset setting. To set the proportional bandwidth, multiply the current bandwidth setting by 1.5 and use it as your new bandwidth setting. The system should come into control and maintain a steady temperature near the setpoint. Integral Reset monitors the difference between the set point and the actual temperature. Its function is to slowly change the output power until the delta between actual temperature and set temperature is zero. 11
The function works by integrating the error signal at fixed intervals. These intervals are expressed in repeats/minute. The acceptable is 0.01 to 10 repeats / minute. Start with a setting determined by the following formula. Integral Reset = 1/ 2(period) Note: Period is expressed in minutes. Example: The system s period of oscillation with narrow bandwidth was 75 seconds. Therefore the suggested Integral Rate is Integral Reset = 1/ 2(1.25 minutes) Integral Reset = 0.4 repeats/minute For slower response reduce the number of repeats per minute. NOTE: DERIVATIVE RATE IS DIFFICULT TO APPLY. IF YOU ARE NOT EXPERIENCED IN PROCESS CONTROL, ASK FOR HELP NOW! Derivative Rate senses the rate of change of the temperature and allows the controller to anticipate power needed to compensate for rapid changes in system loading. This term is generally used only on very sluggish systems or where very quick response is necessary. The acceptable range is 0.01 to 10 cycles/minute. To determine an appropriate derivative rate, use the following formula. Derivative Rate = Integral Reset / 10 For the example above the Derivative Rate would be.04 cycles per minute. The Derivative function is difficult to use and often causes more trouble than it is worth. 12
May 2003 Oven Industries, Inc. Mechanicsburg, PA 717-766-0721 www.ovenind.com