PID regulation PT

[Sprudle]

Hello

 

Does someone have a good way to control pressure using PID in cx-programmer?

I got two pumps and one PT(4-20mA)

Half the year only one pump need`s to run (about 3bar)

 but in the season (i work in a fabric) two pumps need to be running (about 4bar needed) except in the night.

I`m going to use HMI for adjusting the setpoint so there is no need for any clock/date for this to change itself.

The question is how to get one of the pumps to shut down when the need for pressure is not so high. And get the pumps to change "main" pump sometimes so one pump is not running all the time.

 

Hope this was understandable