PID TEMP

Hi Need some help on PID 

i am using s7-1200 plc 1214dc/dc/dc 

i want to control temperature ,situation is like i have cooling unit running continuosly in a chamber and i am using pid for heating unit in the same temperature i have set point of 22 degree centigrade

Now problem with me is pid temp is not functioning properly temperature is varying between 16 to 28 degrees Celsius any suggestions on why it is not working properly 

Regards 

Hi,

try the following - reduce the P-value and if it get´s better increase integration time - empirical dimensioning.

Regards,

Towome

Thanks Towome this was very helpful it workd 

now setpoint is 22 degree celcius 

and its lower limit is 21.1 and upper limit is 23.1

needs a bit fine tuning ...

New question published by adnan2015engineer is split to a separate thread with the subject What is responsible for quick response of PID compact?.

Best regards
Jen_Moderator