MORE INFO S7300 plc PID control for modulating burner motor

[Tweed]

Hi
can anybody help with the PID control of the modulation motor for gas burners.The system at the moment is controlled with eurotherm 818 controls but we are upgrading the whole system on to siemens s7 300 plc and would like to do away with the eurotherms and use the plc with a HMI screen.Would be greatfull for any help on the function blocks required etc.

The gas burners control a 5 hood film drier. The modulating motor is a honeywell M941B with pot feedback 0-10v the open and close signals are digital 24vac supplied from the eurotherm at the moment.The temperature feedback PV is from a PT100 probe in each of the hood ductings.The gas management side will be of the burners will remain as standard and will interpose the burner starting seq. with a relay fired from the plc.

 

[TheControlGuy]

Hey Tweed;

What are you looking for exactly; the Gain, Ti, Td, ...

Sounds like an interesting project..

 

[torontogill]

Hi Tweed

the function block you require in step 7 is FB41, I have never used this FB, so I can't help you much there.

I know that this has been discussed at Phil Melore's site (

http://www.plctalk.net/qanda/

), it might be worth your while having a visit and posting your question there. I know there are lots of guys who are very good on Siemens S7 and on PID's in general.

Paul