The PackMLBaseStateMachineType is the top level StateMachine for PackML. It is illustrated in Figure 16. The TR-88 specification does not define an initial State for this StateMachine, but typically the state machine uses either the Aborted or Stopped State as an initial State. Annex B provide recommended display names for the various states.

image020.png

Figure 16 - PackMLBaseStateMachineType illustration

The PackMLBaseStateMachineType defines the available states in a PackML system. The type is defined in Table 6. StateTypes and TransitionTypes only exist in the type system, thus they do not have a modelling rule.

Table 6 – PackMLBaseStateMachineType Definition

Attribute

Value

BrowseName

PackMLBaseStateMachineType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the FiniteStateMachineType defined in OPC 10000-5

HasComponent

Variable

0:AvailableTransitions

NodeId[]

BaseDataVariableType

Mandatory

HasComponent

Variable

0:AvailableStates

NodeId[]

BaseDataVariableType

Mandatory

HasComponent

Object

Aborting

StateType

HasComponent

Object

Aborted

StateType

HasComponent

Object

Cleared

StateType

HasComponent

Object

MachineState

PackMLMachineStateMachineType

Mandatory

HasComponent

Object

AbortedToCleared

TransitionType

HasComponent

Object

AbortingToAborted

TransitionType

HasComponent

Object

ClearedToAborting

TransitionType

HasComponent

Method

Abort

Defined in 6.7.5

Optional

HasComponent

Method

Clear

Defined in 6.7.6

Optional

The AvailableTransitions and AvailableStates are optional variables in the FiniteStateMachine, but they are overridden in the PackMLBaseStateMachine and are made Mandatory. The PackMLBaseStateMachine does include a sub-state machine that provides sub-states for the Cleared State.

Aborting - The ABORTING state can be entered at any time in response to the Abort command or on the occurrence of a machine fault. The aborting logic will bring the machine to a rapid safe stop. Operation of the emergency stop will cause the machine to be tripped by its safety system. It will also provide a signal to initiate the ABORT State. The value of this StateType is 8.

Aborted - This state maintains machine status information relevant to the Abort condition. The machine can only exit the ABORTED state after an explicit Clear command, subsequently to manual intervention to correct and reset the detected machine faults. The value of this StateType is 9.

Cleared – this state exposes the MachineState sub StateMachine and state associated with this substate machine. The value of this StateType is 19.

MachineState – A PackMLMachineStateMachineType defined in section 6.3.7.

Abort – a Method to trigger a change of state to Aborting. This will affect all sub-states in cleared state. Defined in 6.7.5.

Clear – a Method to trigger a change of state to the Cleared. Defined in 6.7.6.

Table 7 defines the available Transitions in the PackMLBaseStateMachineType.

Table 7 – PackMLBaseStateMachineType Additional References

Source Path

Reference Type

Is Forward

Target Path

ClearedToAborting

ToState

True

Aborting

FromState

True

Cleared

HasCause

True

Abort

AbortingToAborted

ToState

True

Aborted

FromState

True

Aborting

AbortedToCleared

ToState

True

Cleared

FromState

True

Aborted

HasCause

True

Clear