LogRecord structure – Part 26: LogObject

5.5 LogRecord structure

This structured DataType describes the required information in a LogRecord. An array of this structure type is returned as a field in a structure in the LogObject GetRecords Method call.

The structure is formally defined in Table 8.

Table 8 – LogRecord structure

Name	Type	Description	Optional
LogRecord	Structure	Subtype of Structure defined in OPC 10000-5
Time	0:DateTime	Time associated with this record.	False
Severity	0:UInt16	Is a number between 1 and 1000 inclusive and corresponds to the range provided in the OPC UA BaseEventType (see OPC 10000-3). Additional details for mapping of the severity defined for OPC BaseEvents to LogRecords is described in Table 9.	False
EventType	0:NodeId	Describes the specific type of Event. It corresponds to the EventType field defined in BaseEventType. If AdditionalData is provided then an EventType should be provided.	True
SourceNode	0:NodeId	Identifies the Node this record originated from. If the LogRecord is not related to a specific Node then this shall be set to a null NodeId.. Additional rules may be defined by other specifications that utilize the LogObject.	True
SourceName	0:String	Provides a description of the source of the LogRecord, this could be the string-part of the BrowseName of the SourceNode.	True
Message	0:LocalizedText	Provides a human-readable and localizable text description of the occurrence that is being represented in the LogRecord.	False
TraceContext	0:TraceContextDataType	This structure is used to correlate records inside of a Server along with corelating records between other Servers and Clients. The TraceContextDataType is described in 5.6.3.	True
AdditionalData	0:NameValuePair[]	Additional data for the log entry. This field contains the additional event fields of an LogEvent.	True

Severity ranges for Alarms and alerts are discussed further in OPC 10000-9. Table 9 provides the Severity ranges that shall be used for LogRecords. Other specifications, vendors or end users may further subset these ranges or generate thier own names for the ranges. For example, the Emergency range described in SYSLOG is commonly used for process alarms and would have multiple sub ranges defined by end users. In the manufacturing industry, typically the SYSLOG Alert range would be considered as Warnings and the Emergency range would have been renamed Error and have multiple sub ranges (i.e. CriticalError, MiniorError...).

Table 9 – LogRecord Severity Mapping

Syslog Names	Severity Range	Diagnostics classification
Emergency	401 – 1000	Incidents that are potentially fatal to the overall process/system and need to be addressed immediately.
Alert	300 – 400	Incidents that affect the overall process/system and need to be addressed.
Critical	251 – 300	Incidents that could affect the overall process/system and needs to be addressed.
Error	201 – 250	Incidents that have negative effects but does not affect the overall process/system.
Warning	151 – 200	Incidents that should be noted but need not be addressed.
Notice	101-150	Significant or unusual or unexpected successful incident.
Information	51-100	General information.
Debug	1-50	Verbose tracing information that can be used to debug the flow of an application.

The LogRecord representation in the AddressSpace is formally defined in Table 10

Table 10 – LogRecord definition

Attribute	Value
BrowseName	LogRecord
IsAbstract	False

References	NodeClass	BrowseName	DataType	TypeDefinition	Other
Subtype of the 0:Structure defined in OPC 10000-5

ConformanceUnits
LogObject Base