Mickey
Lifetime Supporting Member
The PID instruction has a build-in "SCP" instruction.
What that means is if you put values of 0-32767 for the "input Range Maximum" and "Input Range Minimum" it will be scaled to whatever is enter into the "Engineering Unit Maximum" and Engineering Unit Minimum". In your case 0-100. The result of this scaling is displayed as the Process Variable status value. And then used to calulate the error vs the setpoint for control.
14049/32767= .4287
.4287*100= 42.87 deg
Save the program and post it here when the error occurs.
Please see pdf below about loop update time, your program updates the PID instruction every scan but the "Loop Update Time" is set for 2 sec.
What that means is if you put values of 0-32767 for the "input Range Maximum" and "Input Range Minimum" it will be scaled to whatever is enter into the "Engineering Unit Maximum" and Engineering Unit Minimum". In your case 0-100. The result of this scaling is displayed as the Process Variable status value. And then used to calulate the error vs the setpoint for control.
14049/32767= .4287
.4287*100= 42.87 deg
Save the program and post it here when the error occurs.
Please see pdf below about loop update time, your program updates the PID instruction every scan but the "Loop Update Time" is set for 2 sec.
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