Long distance PID feedback loop

The case is having the plc in a place that is 10Km distance from the pressure transmitter which is the PV to the PID ,so the response take a ong time,when we increse the speed of the pump by giving SP the response take time and it became more than the SP.
how to slove this?

PID tuning

It seems to me that you should "tune up" PID parameters.

You should read following topic:
http://www.plctalk.net/qanda/showthread.php?t=3560
Good luck

Hello maher731;
You are adding a delay to your process through the time-gap of the response time on your transmitter.
Can you reduce the delay, say change the transmission parameters of the signal from the pressure transmitter? Think of dedicated-line modem, RF transmission (look at Siemens WiPS system, for example:
http://www.sea.siemens.com/instrbu/docs/pdf/wireless_solution_cutsheet.pdf)...

If you plan to try to compensate for this delay in your program, you can always try Feedforward control, or making the derivative parameter of the PID controller large enough to anticipate the changes in PV. But that sould be done by an experienced engineer.
Hope this helps,
Daniel Chartier

Thank you

Get rid of PID, use a simple comparison with time delays.