BACnetStack_AddGroupObject

bool BACnetStack_AddGroupObject(const uint32_t deviceInstance, const uint32_t groupObjectInstance);

Creates the stack-held data for a Group object so the stack serves List_Of_Group_Members reads (and AddListElement/RemoveListElement) natively.

The only Group properties that are handled and stored by the CAS BACnet Stack are:

• ObjectIdentifier, ObjectType, PropertyList
• ListOfGroupMembers (maintained by BACnetStack_AddGroupMember() and BACnetStack_RemoveGroupMember(), and by a client WriteProperty, AddListElement or RemoveListElement)

Callbacks are used for:

    --------------------------------------------------------------------------------
    Property            Datatype            Callback
    --------------------------------------------------------------------------------
    ObjectName          CharacterString     CallbackGetPropertyCharacterString
    Description*        CharacterString     CallbackGetPropertyCharacterString
        (*) Optional; enable it with BACnetStack_SetPropertyEnabled first.
    --------------------------------------------------------------------------------

PresentValue - a BACnetLIST of ReadAccessResult, required by 135-2024 cl. 12.14.6 - is built by the stack itself from ListOfGroupMembers: one ReadAccessResult per member, carrying the read result of every property BACnetStack_AddGroupMember() referenced for that member. A member’s own property-read failure is reported as a per-property Error inside its ReadAccessResult, not a whole-read failure.

Note

Requires the STACK_OPTION_OBJECT_TYPE_GROUP build option.

See also: BACnetStack_ObjectExists(), BACnetStack_RemoveObject()

BACnet reference: ANSI/ASHRAE 135-2024 clause 12.14 (Group Object Type).

Parameters

Parameter	Direction	Description
deviceInstance	in	The device instance that owns this Group object.
groupObjectInstance	in	The instance of an existing Group object (add it with BACnetStack_AddObject() first). An instance with no Group object fails the call; it used to create a Group engine that served nothing.

Returns

True on success; false if the device does not exist, the Group object does not exist, the instance is 4194303 or above, memory for the Group could not be allocated, or Group support is not compiled.

Topic: Schedules, calendars, trend logs and other object configuration. Declared in CASBACnetStackDLL.h.