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Ctrl-Z in Control Studio - how to recover alarm associations?

Hello DeltaV community!

I teach students DeltaV and we often run into a problem with Control Studio and undo.

If you use ctrl-Z (undo) after making a change to a PID1 block parameter, all 'associations' with the PID block are lost - that is, alarms lose their connection to the alarm parameters (e.g. HI_HI_ACT, etc) and any History Collection points being read from the PID block are deleted. It's almost as if undo deletes the PID block then pastes in a new block, reconnects the connectors, and sets the parameters and block name to what was previously there. It successfully un-does the last change, but there is collateral damage.

My students don't realize there's a problem until they go to download and Duncan informs them all their alarms are not associated with a parameter. The module is saved before the download is attempted, so they are stuck with the disconnections.

To reconnect the alarms, I have created a custom .fmt import-format file and import the pid_loop alarm parameter defaults - it’s a clunky recovery (and only reconnects the parameter and alarm message parameters, not the conveniently displayed limit value, although the limits work). 

Is there a better solution to ‘reconnect’ the alarms back to the way they look in the module template?

 

I can provide screenshots if I’m not being clear.

Many thanks,

Chris

2 Replies

  • I'm not sure what version you are using but for v13.3 and v13.3.1 this behavour is listed as known issue TFS227316 in the release notes NK-1600-0334 or NK-1500-0151. It seems to affect any function block where an alarm is assigned to a parameter, not just PID. The full description is below. However the Prevention procedure doesn't seem to work for me. Even if I save, close and reopen after assigning an alarm, the issue still occurs when I change a parameter and then undo.

  • Do you have VCAT enabled? It's a clunky workaround, but if you check in the module then check it back out before making any changes to the PID1 block, you can always roll back to a previous version rather than undo.