Reply To: Limiting CV while maintaining controller in program mode

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Be careful when you use the CVlimit what i have found is when using limits the error still builds so if your PV is below (or above) the SP as soon as you release the limit it will jump to the new limit range. For example if you limit it to 25% and at some point in the process you send the limit to 75% if the PV is below the SP the CV will jump to 75%. This works in the opposite as well if you are limiting it to 25% closed when you send the limit to 0% the CV will follow. I’ve talked to AB tech support about this as well they were as puzzled as I was. For applications that I’ve used the CV limits in I’ve I ensure that I put in a 1 second timer that upon sending a new limit I place the loop in manual while the timer times and send the previous limit to the CVProg.