ddeshi2
Member
Hi guys,
We are using a sliding gate valve with digital positioner to feed air to our system. The process requires air to be supplied slowly for every few minutes and I'm using PID loop with a Timer On Delay to slowly open the valve and ramp up to desired flow rates. It works fine. When the operator presses Stop Button, the same valve has to go to zero instantly. My question is, how can I achieve this? can I use different PID constants for the start up and stop procedures for the same PID loop (by using a MOV statement)? If so, which PID constant should I change to close the valve quickly - Kp, KI or Kd? I'm not using Kd in my start procedure. Please help!!!
Thanks,
Andy
We are using a sliding gate valve with digital positioner to feed air to our system. The process requires air to be supplied slowly for every few minutes and I'm using PID loop with a Timer On Delay to slowly open the valve and ramp up to desired flow rates. It works fine. When the operator presses Stop Button, the same valve has to go to zero instantly. My question is, how can I achieve this? can I use different PID constants for the start up and stop procedures for the same PID loop (by using a MOV statement)? If so, which PID constant should I change to close the valve quickly - Kp, KI or Kd? I'm not using Kd in my start procedure. Please help!!!
Thanks,
Andy