BACnetStack_AddEventLogObject

bool BACnetStack_AddEventLogObject(
  const uint32_t deviceInstance,
  const uint32_t objectInstance,
  const uint32_t maxBufferSize);

Adds a BACnet Event Log Object.

The device must be added first. Records accumulate from received event notifications. Each record advances Total_Record_Count, the property the BUFFER_READY event algorithm monitors.

The Event Log properties that are handled and stored by the CAS BACnet Stack are:

• Enable, Stop_When_Full
• Buffer_Size, Record_Count, Total_Record_Count
• Notification_Threshold, Records_Since_Notification, Last_Notify_Record
• Log_Buffer, Object_Identifier, Object_Type, Status_Flags, Property_List These are answered from stack storage BEFORE any callback is consulted, so a registered Get callback CANNOT override them, and writes to the writable ones land in the same storage rather than in a Set callback. Start_Time and Stop_Time are also stored by the stack, but this function does NOT enable them (they are optional in cl. 12.27). Until BACnetStack_SetPropertyEnabled() is called for them, a read returns Error(PROPERTY, UNKNOWN_PROPERTY). Once intrinsic BUFFER_READY reporting is enabled, Notification_Threshold, Records_Since_Notification and Last_Notify_Record are served by the event algorithm instead of by this object’s own members, for both reads and writes. Log_Buffer records are retrieved with ReadRange. As for the Trend Log, a ReadProperty of it returns Error(PROPERTY, READ_ACCESS_DENIED).

Callbacks are used to handle the remaining required properties. The following list contains those properties and the Callbacks that are used to get the required data:

    --------------------------------------------------------------------------------
    Property            Datatype            Callback
    --------------------------------------------------------------------------------
    ObjectName          CharacterString     CallbackGetPropertyCharacterString
                                            CallbackSetPropertyCharacterString
                                            (only if made writable)
    EventState*         Enumerated          CallbackGetPropertyEnumerated
        (*) Served by the stack's intrinsic alarm engine instead, if intrinsic reporting has been
        enabled for this object.  With neither an alarm engine nor a callback the stack
        answers NORMAL.
    --------------------------------------------------------------------------------

Note

Requires the STACK_OPTION_OBJECT_TYPE_EVENT_LOG build option.

See also: BACnetStack_ObjectExists(), BACnetStack_RemoveObject()

BACnet reference: ANSI/ASHRAE 135-2024 clause 12.27 (Event Log Object Type).

Parameters

Parameter	Direction	Description
deviceInstance	in	The instance of the device that the event log object is added to.
objectInstance	in	The instance of the event log object being added.
maxBufferSize	in	The maximum number of records to maintain in memory.

Returns

Returns true if successful, false if failed.

Topic: Objects and properties. Declared in CASBACnetStackDLL.h.