All Services in this Service Set for Servers that support auditing may generate audit entries and shall generate audit Events for both successful and failed service invocations if the invocation modifies the AddressSpace, writes a value or modifies the state of the system (alarm acknowledge, batch sequencing or other system changes). These method calls shall generate an audit Event of type AuditUpdateMethodEventType or subtypes of it. Methods that do not modify the AddressSpace, write values or modify the state of the system may generate events. See OPC 10000-5 for the detailed assignment of the SourceNode, SourceName and additional parameters.

For Clients that support auditing, accessing the Method Service Set shall generate audit entries for both successful and failed invocations of the Service, if the invocation modifies the AddressSpace, writes a value or modifies the state of the system (alarm acknowledge, batch sequencing or other system changes). Invocations of the other Methods may generate audit entries. All audit entries should be setup prior to the actual Service invocation, allowing the invocation to contain the correct audit record id.