PID Temperature Controller

PID tuning

The set of appropriate PID values depends on the used sample heater and cooling configuration. Ask beamline staff to set the last known PID parameters. Check the quality of the temperature control (straight-line control, no overshoot or undershoot). If required, re-tune the PID parameters as follows.

1. Disable Setpoint ramp limit if it has been enabled.
2. Set reasonable manual output limiton the Elind or Sorensen potentiometer, as the controller will set maximum allowed power output at the beginning of the tuning procedure.
3. Access Full operation level (toggle switch 6 in up position).
4. In the ‘Atun’ list, select ‘drA’ and set it to ‘off’.
5. In the ‘Atun’ list, select ‘tunE’ and set it to ‘on’.
6. Press the Page and Scroll buttons together to return to the Home display. The display will flash ‘tunE’ to indicate that tuning is in progress.
7. Select Auto mode pressing Auto/Man button and set the setpoint to the value at which you will normally operate the process.
8. After some seconds (maybe >1min), the controller induces an oscillation in the temperature by first turning the heating on, and then off. The first cycle is not complete until the measured value has reached the required setpoint.
9. After two cycles of oscillation the tuning is completed and the tuner switches itself off.

Calculating and setting the value of the PID parameters in order to obtain a good control is described in detail in Chapter 4 of the Installation and Operation Handbook (Eurotherm 2408).