Room operating mode (ROpMod) is determined by central functions (for example, scheduler) and can be overwritten by a local presence button on the room unit. The room operating mode is a multistate BACnet Object that supports the following room operating conditions:

  • Comfort (occupied)
  • Pre-Comfort (standby offset)
  • Economy(unoccupied)
  • Protection (extended unoccupied period)

Plant operating mode (PltOpMod) is determined by the room operating mode and can be overridden by central request for Warm-up, Cool down or Night cooling, and so on. The plant operating mode is a multistate BACnet Object that supports up to 17 different plant operating modes. Rooms typically use the following plant operating modes; Off, Comfort, Pre-Comfort, Economy, Warm-up and Cool down.

HVAC device mode determination – The plant operating mode is used to determine the device mode (the operating state) for each HVAC device controlled in the room segment. The HVAC device mode is a multistate BACnet object that supports the operating states of HVAC devices. Typically each device is assigned operating modes (for example, Off, Control mode, Fully Open). When the HVAC device is in Control mode it is under the control of the Room HVAC coordination functions. For additional information see ABT Site Help, Technical principles > Operating modes.

Example of VAV application type with Lights and Blinds for a Room with one Room Segment.