I have to adjust 10 PID loops and done some relay tuning exercises with my S7 program.
I had obtained the Ultimate Gains (Ku) and Ultimate Periods (Pu) of my PID's with relay tuning method.
I would like to know, what is the relationship between my relay tuning results and the Siemens PID parameters. I am using some FB58 and some FB41.
For example one of my relay tuning result for FB58 is:
Ku = 101.86%per deg C
Pu = 120 sec
According to Zeigler-Nichols rule of tuning constants, I get:
Gain = 61.12% per deg C(by 4d/a.pi), Ti = 60 sec (by Pu/2) , Td = 15 sec(by Pu/8)
What are the corresponding parameters for implementation in FB58, if the cycle time of PID is 0.4 sec:
Gain =?, TI =?, TD=?
In the FB58, there is a parameter D_F which is quite interesting in this case.
Thank you for your help in advance.