Automated Logic WebCtrl and BACnet Schedules

The new BACnet SendExceptionSchedules action in Events2HVAC was designed to push dynamic schedules from E2H to HVAC controller schedules. However, this is NOT recommended for Automated Logic WebCtrl HVAC systems without the use of the new ALC Scheduling Add-On (See update at bottom).

From ALC Support:

"In Webctrl, when you are viewing schedules, we are pulling the schedules from the database to create the graphs.  Webctrl doesn’t pull schedule information from the module to create the graph.  So we cannot display third party schedules in Webctrl."

Here's what we discovered when trying to send schedules from E2H to WebCtrl at a customer site:

  • WebCtrl will delete out ANY schedules in the schedule object prior to adding or deleting a WebCtrl Schedule, so any schedules from E2H will get removed until the next schedule update.
  • E2H will write classroom schedules to the schedule object every x hrs and preserve any event schedules that are already in the schedule object (from WebCtrl)
  • WebCtrl uses event priorities 13,14,15 only when it writes to the schedule object.
  • We added total and daily schedule limits to E2H to match the default limits of schedules in ALC and prevent errors when downloading schedules. (30 total and 6 daily schedules)
  • WebCtrl does not show any schedules that were added by E2H to the schedule object (operator can't see schedules added by E2H in WebCtrl).

The Optimal Start/Stop feature in WebCtrl will still see any schedules that were added by E2H or WebCtrl so this will still work, but the user won't know what schedules are affecting the module.  Even worse, any schedule (override, holiday, etc.) entered by the WebCtrl user will erase any schedules that E2H had previously sent to it.

In Summary:

For Automated Logic HVAC systems, we recommend using the normal StartStop action to write to the zone occupancy BV point instead of pushing schedules to the zone schedule object using the SendExceptionSchedule action.

Update July 2017:
ALC has created a new BACnet Scheduling Add-on to address the issues found above.  This has been successfully tested and is now the recommended path for Events2HVAC integration to WebCtrl.  Please contact your ALC representative to get more details on the add-on.

 

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