haris_usama

Dear All,

I have been trying to configure a PID CONT_C block FB41 but cannot make it work.

I call the block in OB35, set the Cycle time to 100ms => which is the same as the OB35 Cycle time mentioned in the cyclic interrupts in the CPU configuration. I am using s7-300 314.

I give the SP as 50.0, give PV = 20.0 (from PLC SIM) and try to read the output but get "0". It gives me effective PV and error correctly and also individual components of P,I (Since I am only using a PI controller and not derivative action).

I have downloaded the program, including the DB. Is there something wrong that I am doing?

Regards,

Haris

if you want an output at the PID block manually, Set the "MAN_ON" parameter active and feed a desired value at "MV" and if you want to control it automatically, remove "MAN_ON", enable "P_SEL" and "I_SEL" and also feed the "GAIN" and "TI" values. it will just simply work

New question published by tomnass is split to a separate thread with the subject Cont_c configuration.

Best regards
Min_Moderator

Dear all,

i am a beginner in using PLC and i want to make aprogram to control modulated valve (0-10)volt using a feedback sensor(4-20)ma using PID.

it will be great if anyone can help me with example.

thanks in advance

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