This OPC UA Variable represents the BACnet property Log_Buffer. It represents a list of logged values and can only be accessed with with the BACnet service ReadRange. Therefore, the OPC UA representation requires the AccessLevel HistoryReadable to allow access of the logged values through OPC UA Service HistoryRead (see Table 40).

The current value is not readable since it is not provided through BACnet directly. The BACnetUaMapper may provide the current value by reading the referenced BACnet property that is logged by the BACnet Trend Log object. In this case the AccessLevel can also have the Readable flag set.

Table 40 – Log_Buffer Attribute definition

OPC UA Attribute	Value
BrowseName	Log_Buffer
AccessLevel	HistoryReadable
Historizing	True if BACnet property Enable is True and the current time is between the BACnet property values Start_Time and Stop_Time