PlantPAx PIDE CV Locking

Hi folks,

I'm new here, but I'd been lurking for nearly a year... The company I work for is diving head long into a project with ControlLogix running PlantPAx AOIs/HMI objects. I'm an old Bailey DCS guy with some SLC experience back in college, so I'm trying to find my way in ControlLogix.

We just brought a portion of our new facility up and I was asked if we could lock the CV of a PIDE while a certain process condition exists. From what I've seen the PIDE from PlantPAx is essentially a PIDE that they offered before with a wrinkle or two. I could easily lock the value with some external piece of logic but I'm looking for the right way to do this so we can be consistent with what the operator sees on his HMI versus the actual state of the process and consistent in the way we do this going forward. I've been doing a lot of experimenting but just can't seem to quite get what I want.

Any thoughts on this?

What exactly do you mean by CV locking? A constant CV value? If so, put the PIDE in Manual and set a CV value.

I figured that would be the answer.

As I've said I'm more familiar with Bailey, and when using a PID/Station block combination I can use what's call control output tracking which is a single boolean that never pulls the loop out of the mode to lock the control output during a particular process condition. The reason I'm looking to avoid this is because in PlantPAx the HMI global objects indicate the Manual as being an abnormal condition when you open the faceplate. So I was hoping to do this without the operator seeing and abnormal condition so that we don't get nuisance calls. But, I need to adjust too I guess.

What about "hand", when in hand you can set the CV to a constant, and have bump less transfer back to mode before hand was activated.

It sounds like you want 'Override' not 'Manual'.

Regardless, I think the control indicator is going to change not matter which mode you use...

Putting the controller seems to work pretty well. It does show a hand symbol on the HMI but its not the flag that indicates that the loop isn't in the normal control mode. Thanks for the suggestion this may be what I implement.