7.10 OperationStateMachineType Definition

The OperationStateMachineType provides an abstract state machine for operation. The state machine can be used for entities whose states can be represented by Idle, Ready or Executing and which can be started and stopped.

At the system and task control levels, concrete state machine types are derived from the OperationStateMachineType. The states of these state machines can be further enhanced with Substate machines.

The overview of the state machine with all transitions is shown in Figure 19.

Figure 20 shows the OPC UA representation of the OperationStateMachineType, the transitions between the states have not been shown for the sake of simplicity. The OperationStateMachineType is formally defined in Table 65.

The states of the OperationStateMachineType are described in Table 28.

The component Variables of the OperationStateMachineType have additional Attributes defined in Table 30.

The Variable LastTransitionReason provides the reason for the LastTransition. The EnumValue and ValueAsText of this 0:MultiStateValueDiscreteType are described in Table 29. This specification does not define an explicit error state. The LastTransitionReason indicates if a state change was caused due to an error.

The component Variables of the OperationStateMachineType have additional Attributes defined in Table 30.

LastTransitionReason EnumValues 1 and 2 describe where an operation was initiated, which reasoned the last transition. External means that the operation was initiated by a control station, which is not part of the robot system, e.g a cell PLC. Direct means that the operation was initiated by a control station, which is part of the robot system, e.g. the teach pendant.

The Variable PossibleStopModes is an array of EnumValueType, which contains a list of supported stop modes (see Table 31).

The Variable ConfiguredDefaultStopMode is an integer, which contains the value of the configured stop mode for this system. This shall be one of the values in the PossibleStopModes array.

The Variable LastTransition, inherited from the FiniteStateMachineType, is defined as mandatory in the OperationStateMachineType.

The transitions of the OperationStateMachineType are described in Table 33.

The components of the OperationStateMachineType have additional references which are defined in Table 69.

The component Variables of the OperationStateMachine have additional Attributes defined in the table below.

7.10.1 Start Method

The signature of this Method is specified below.

Signature

	Start (
	[out]	0:Int32	Status
	);

The Start Method is called by a Client to start execution of the entity which is represented by the state machine.

The possible Method result codes are formally defined in Table 37.

The Start Method representation in the AddressSpace is formally defined in table below.

7.10.2 Stop Method

The signature of this Method is specified below.

Signature

	Stop (
	[in]	0:Int64 	StopMode
	[out]	0:Int32	Status
	);

The Stop Method is called by a Client to stop execution of the entity which is represented by the state machine.

The possible Method result codes are formally defined in Table 40.

The Stop Method representation in the AddressSpace is formally defined in the table below.