fast PID controls on Siemens S7-300.


Thread Starter

Roberto Finazzi

I need to perform 2 fast PID controls on a Siemens S7-300 plc. The controlled system has a cut frequency of about 25Hz and so the PID
sample time must be at least 4 ms; for this the FM355 PID module seems too slow.
I saw that in the S7-314 IFM cpu there is a SFB (SFB41) for PID controls with a sample time >= 1ms but what time it takes for a cycle (CPU time)?
Is possible to put out the manipulated value on any analog output (SM332) or this must be done only on the integrated analog output?
Is this the only one method to perform a fast PID on a S7-300?