why the PID loop is not controlling immediately, even when the PID output is showing 100%

Graeme

Hey Amel, I too have struggled with the PID start delay.
My PID loop controls pressure brilliantly "ONCE" it starts, butwhen my pump starts with a minimum fixed frequency, there can be from 5 to 30 seconds before the PID becomes active and starts to control the process.

This was frustrating, because I had a pump set with a Duty-Assist configuration, and when the duty pump started, the required delivery pressure was not reached in time (about 10 seconds), so the assist pump starts before the Duty pump can accelerate under PID control.

I tried many different things, like giving the PID active (P2200) a rising edge from a timer, 1 second after the pump starts. This made no difference. I also wondered if the PID error must be a minimum value before the loop is active, but this also made no difference.

I still do not know why this happens.
Regards,
Graeme