Change a controller from auto to manual and vise-versa


#1

Pneumatic controllers :While taking the controller from auto to manual, the manual output is to be balanced to the auto output and then transfer the auto-manual switch to manual. While changing the controller from manual to auto, the controller set point is matched to the manual output and then auto-manual switch is transferred.
Electronic controllers :Auto to manual control may be transferred directly as the electronic circuit keeps the auto and manual output matched. But while changing the controller from manual to auto, the controller set point is to match to the process variable and then auto-manual switch is transferred