Setpoint returns the setpoint value output this VI calculates from the setpoint profile and from the elapsed time since the first call or reinitialization of this VI. Reinitialize? specifies whether to reinitialize the output to the setpoint profile at time t = 0. If dt (s) must be less than 1 ms, specify the value explicitly. If dt (s) is less than or equal to zero, this VI calculates the time since it was last called using an internal timer with 1 ms resolution. Setpoint specifies the setpoint values in the setpoint profile.ĭt (s) specifies the loop-cycle time, or interval in seconds, at which this VI is called. Specify the time (s) values in ascending order. Time (s) specifies the time values in the setpoint profile. To understand how to set the PID values is outside the scope of this exercise but information on PID tuning is readily available from the web or textbooks on control.Setpoint profile specifies an array of time and setpoint value pairs that define the profile of the setpoint as a function of time. You can experiment with different set points as well as different PID values.Use the P, I and D values as shown in the front panel. Set the control temperature between T amb and T max that you measured earlier. Observe the temperature reading, is it giving the correct values? If yes, then you are ready to set the temperature and put the heater under PID Control.If you observe the LED intensity changing,your circuit is connected OK. When you change the manual heater setting dial, the gauge output and the LED intensity will change. This will set the heater output to manual override. As the load resistor is not designed to be a heating element, you may not be able to heat up the area around the thermistor to above 38 C (this will depend on the environment of the room you are working in).If you have connected the optional LED, the LED intensity should also change as you adjust the heater output. One way to check the your circuit is to observe the temperature when you change the PWM output.Note that setting the PWM output to 0 turns off the heater and 100 turns on the heater completely. The VI also allows you to control the heater output manually by setting the manual override.The PID output is between 0 to 100% and is used to drive the PWM output.In normal operation, this measured temperature value is then compared with the set value to generate the PID output.The sub VI Temp Control Thermistor.VI returns the temperature in Celsius as measured by the thermistor.The VI first configures the EMANT300 to use the PWM output rather than the counter.LabVIEW Front Panel LabVIEW Block Diagram Python for Android, Windows, Raspberry Pi, Ubuntu.

Labview pid control block diagram