Re: Split Control PID loop
Other Software
Split Control PID loop
paulmatty
04-22-2005, 7:09 AM
I need to have split control over a heating and cooling system. The theory is, We have a sand bath with an electric heating coil and an air cooling coil. When heating is required the PID output should be directed to the heating coil. When cooling is required the PID output should be directed to the cooling coil. When heating the output can be 0 to 100% (4-20mA) When cooling the output can be 0 to 100% (4-20mA) There is no need for clamping. When the heating circuit is on then the cooling circuit should be off (0%) When the cooling circuit is on then the heating circuit should be off (0%) I can not see a way to do this simply within ioControl, I have been given some OPTOscript by the lovely people at System Devices in the UK and I simply wondered if there was a simpler way that anybody had come across to do this split control without using ioControl and OPTOscript programming.
Re: Split Control PID loop
jigar_bm@yahoo.co.in
06-19-2008, 8:42 AM
Hi Paul,
I am also working with same kind of application.and i am also stuck at same point. but i think by using only script you can solve this kind of problem. still i stuck at some point.lets see.
-jigar
Re: Split Control PID loop
jigarbm
06-23-2008, 4:58 AM
Hey Paul,
I solved that problem. i did small mistake and now i can run 4 PID loop at same time but in Split control. but i also used some programming but i think it was very easy. and i think by using scrip you can split pids.
thanks
JIGAR PATEL
Re: Split Control PID loop
gmitchell
08-19-2008, 9:05 AM
Check out the PLI
piecewise linear interpolator function provided by
Optomations ioControl Functions on the Opto22 website. By setting up two curves to be plotted against the output Q, you can generate 2 new variables that can be connected to separate analog outputs for cooling and heating. Although written for ioControl v5 the subroutines can easily be upgraded to PACControl.
You only work is to plot the values to create the curve/xtraight lines and to include to subroutines in a flow diagram to be scanned at the same speed as your PID update. All the necessary code is prewritten
http://www.opto22.com/site/downloads/drilldown.aspx?aid=1399