PID

[davidtorati 0]

Hello I need help with tuning parameters to a PID function block in a PLC. The application is heating an oven Temperature input is PT100 (RTD) The output is a PWM controlling heating element with Solid State Relay. Starting temperature is about 20 degree (change possibly) Set point temperature 180 degree (change possibly) Reaching time to set point is 10-15 minutes Over shoot temperature about 5 degree How can I get only from this data the critical frequency depending on rising time? And how I decide the parameters: KP (proportional gain) Ki (Integral gain) KD (Derivative gain) How the overshoot and rising time demands affect these parameters? What happened if the set point or the starting temperature is different? Thanks

[Keith Menges 0]

I suggest you read some of the posts here, especially the sections on graphical modelling of the heat exchanger as well as the section about determining gains from the model. I think it will be pretty helpful. However, I don't think the information you have at this point is enough to go on. You will probably need to perform a more structured test. Keith