[Imported] Implement an ON/OFF Delay Timer on a Calculated Point
>>Message imported from previous forum - Category:Scripts and Tips<< User: mchartrand, originally posted: 2018-10-19 17:18:43 Id:146 This is a re-posting from the obsoleted (October 2018) "Schneider Electric Telemetry & SCADA" forum.
**_Chadam: I would like to activate or de-activate a calculated point based on the status of its reference points. E.g. IIF((".Alarm1.CurrentState=1") OR (".Alarm2.CurrentState=1") OR (".Alarm3.CurrentState=1"),1,0)). However, i will like to add an ON delay timer to confirm the "ON" state prior to activating the Calculated point. Similarly an OFF delay timer to confirm the "OFF" state prior to de-activating the Calculated Point. I will like to process the logic on state change of the reference points. Any thoughts?_**
dmercer: I think that you'll be best off doing this in a Function Block Diagram, Ladder Diagram, or Structured Text Program and having it write to an internal digital point.
You can set those to only update on state change, but I don't think that will work well with a timer, as it won't run again to check the timer until there is another point update.
AWoodland: A SFC would certainly be a good solution for this
**Chadam: _Thanks for the suggestions._**
bevanweiss: Please submit a feature request (with ClearSCADA support) to request the extension of the Expression Engine to include TON / TOFF / TP timers 🙂
It would (should) add a vote for my already existing request.
In the meantime, you'd need to use FBD or SFC (or other logic) as mentioned.