Switching between permitted modes

I want to switch between RCAS and CAS using some logic based on operator selection of natural gas or methane.

I am using MODE parameters to do this, but there seems to be something I am missing to make this work.

When the operator switches mode there is a integrity error in the CALC block with it trying to write to the PID1. I can clear the problem by moving the NORMAL MODE from the mode I want to MANUAL. The PID gets written to, the faceplate changes, I am permitted to choose the mode I want.

 So what am I missing that is preventing a nice smooth transition between the modes?

thanks

Gary

  • Thanks.
    I would like the transition to be not dependent on the operator....they flip a switch to choose what gas to use and the DeltaV moves seamlessly to accommodate.
    I am gathering that I would abandon the MODE PARAMETERs and do everything in the CALC.
    I can see where the error of my ways with the MODE.NORMAL.
    I'll give it a try today.

    Gary