DeweyfromOhio
Member
I have a PID loop that seems to accept a new different "temperature setting" each time it toggles in and out software manual-"SWM" I don't use the term "Setpoint" because the Setpoint is written in and does not change. the temperature of this loop is allowed to float above Setpoint due to varying heat gain of the system occasionally it may float 10 degrees above setpoint
This is a discription of my problem, what happens when the circulating pump is told to stop the PID loop for the steam valve is put into -"SWM" with a Set output "SO" of zero. The valve output goes to zero. The temperature will fall in the system. When the pump restarts the SWM and SO are removed and the PID returns to the temperature that it was floating at and MAINTAINS that temperature. up to 10 degrees above actual setpoint. I mean maintain by modulating the CV control valve to that temp. There is Gain and Integral in the PID. There is nothing in Bias or Tieback. Nothing being written to SO Set-Output. Have any of you ever seen this? or is there a way someone programmed some indirect addressing to accomplish this? Thanks for your help.
This is a discription of my problem, what happens when the circulating pump is told to stop the PID loop for the steam valve is put into -"SWM" with a Set output "SO" of zero. The valve output goes to zero. The temperature will fall in the system. When the pump restarts the SWM and SO are removed and the PID returns to the temperature that it was floating at and MAINTAINS that temperature. up to 10 degrees above actual setpoint. I mean maintain by modulating the CV control valve to that temp. There is Gain and Integral in the PID. There is nothing in Bias or Tieback. Nothing being written to SO Set-Output. Have any of you ever seen this? or is there a way someone programmed some indirect addressing to accomplish this? Thanks for your help.