The Program model extends the FiniteStateMachineType and basic ObjectType models presented in OPC 10000-5. Each Program has a Type Definition that is the subtype of the FiniteStateMachineType. The ProgramStateMachineType describes the Finite State Machine model supported by any Program Invocation of that type. The ProgramStateMachineType also defines the property set that characterizes specific aspects of that Program’s behaviour such as lifetime and recycling as well as specifying the result data that is produced by the Program.
The base ProgramStateMachineType defines the standard Finite State Machine specified for all Programs. This includes the states, transitions, and transition causes (Methods) and effects (Events). Subtypes of the base ProgramStateMachineType can be defined to extend or more specifically characterize the behaviour of an individual Program as illustrated with “MyProgramType” in Figure 4.