BACnetWriteGroup (FUN)

FUNCTION BACnetWriteGroup : IEC_BACNET_STATUS

Sends an unconfirmed WriteGroup request. The WriteGroup service is used by a sending BACnet-user to update arbitrary Channel objects Present_Value properties for a particular numbered control group. The WriteGroup service is an unconfirmed service. Upon receipt of a WriteGroup service request, all devices that are members of the specified control group shall write to their corresponding Channel objects Present_Value properties with the value applicable to the Channel Number, if any. A device shall be considered to be a member of a control group if that device has one or more Channel objects for which the ‘Group Number’ from the service appears in its Control_Groups property. If the receiving device does not contain one or more Channel objects with matching channel numbers, then those values shall be ignored. The WriteGroup service may be unicast, multicast, broadcast locally, on a particular remote network, or using the global BACnet network address. Because global broadcasts are generally discouraged, the use of multiple directed broadcasts is preferred.

InOut:

Scope	Name	Type	Comment
Return	BACnetWriteGroup	IEC_BACNET_STATUS
Input	pSourceAddress	POINTER TO IEC_BACNET_ADDRESS	If the BACnet application has only one device constructed and installed, this can be NULL. In this case the MAC address of this device will be used. Otherwise this shall be the MAC address returned on device object construction.
	pDestinationAddress	POINTER TO IEC_BACNET_ADDRESS	This is the MAC address of the device to which the request should be sent.
	pServiceInfo	POINTER TO IEC_BACNET_WRITE_GROUP_INFO	A pointer to the service request information data structure.