PID Proportionnal Valve

[HWICE]

Hi

I'm a bit new with Unitronics.  I try to do a Positionning PID with a temposonic (Analog input) and a proportionnal Valve (4-20mA (12mA = Neutral)).

I did my Autotune but i have a problem with the Output (PID: Control Value - the PID output). If I put my rang to 0@1000 (0@100%), my valve goes only in 1 way... -1000@1000, when the output needs to be neutral, I received -1000. I use a scaling after to take the -1000@1000 to 400@2000 (4-20Ma)

I didn't had time to try the Bit Action (PID: Action: 0: Reverse(Heating-default) 1: Direct(Cooling)). I think if I check my error and if my Actual Position is bigger than my Requested position, i activate that bit. In the same time i use that bit to inverse my Output (PID: Control Value - the PID output).

Is it like that it's supposed to work ?

 

Thanks