The state machines of OPC UA Safety are independent from the actual OPC UA services used for data transmission. This is accomplished by introducing a so-called OPC UA Mapper, serving as an interface between the safety communication layer and the OPC UA stack.

The mapper can either make use of OPC UA Client/Server and remote method invocation or the publishing of and subscribing to remote variables as defined in OPC 10000-14. The requirements on the implementation of the mapper are implicitly given in Clause 6 (OPC UA Information Model).