Grouping is used to implement central control functions and to coordinate demand and forced signals from the various rooms in an entire building, building wing, floor, etc.
Hidden behind the central control functions are system functions, such as operator interventions via BACnet clients, schedulers, automatic reactions, and data from a weather station.
Central functions influence:
- Room operating mode (occupancy and use in room)
- HVAC control via various setpoint requirements depending on the room operating mode
- HVAC setpoints via a weather-dependent adjustment
- Lighting control
- Shading control (blinds)
Grouping can be used to coordinate demand, operating, and forced signals, that is:
- Request signals for hot water distribution (heating circuit)
- Request signals for chilled water distribution (cooling circuit)
- Record demand, operating, and forced signals for the primary air handling unit
Various sources are available for forming these central superposed functions:
- External system or third-party device
- System user via BACnet client
- Building user via BACnet client or local operator unit
- Scheduler or reaction program
- Superposed office based on grouping function
They are distributing after evaluating signals and commands via a Grouping function.
One group master exists for each of the various categories which then forwards the resulting information to all assigned group member (rooms). A group master can for its part be a group member of a superposed group master.