The PackML model when adapted to OPC UA results in a number of StateMachines (see section 6.3.5 for a definition). Instances of these StateMachines may not expose all states and transitions at all times. The actual list of AvailableStates and AvailableTransitions are configured and each instance would be defined by either the end user or the machine builder. The PackML model also includes other meta data such as available mode, current mode, see section 6.3.2 for a complete list

The PackMLBaseObjectType defines a base type that can be used with any machine or object. This base type provides all required information for a working PackML system.

Figure 11 - PackMLBaseObjectType Overview

Table 3 formally defines the PackMLBaseObjectType.

Table 3 – PackMLBaseObjectType Definition

Attribute	Value
BrowseName	PackMLBaseObjectType
IsAbstract	False
Reference	Node Class		BrowseName	DataType	TypeDefinition		ModellingRule	RW
Subtype of the BaseObjectType from OPC 10000-5.
HasProperty	Variable	TagID		String	PropertyType		Optional	R
HasProperty	Variable	PackMLVersion		String	PropertyType		Optional	R
HasComponent	Object	Admin			PackMLAdminObjectType		Mandatory
HasComponent	Object	Status			PackMLStatusObjectType		Mandatory
HasComponent	Object	BaseStateMachine			PackMLBaseStateMachineType		Mandatory
HasComponent	Method	SetUnitMode		Defined in section 6.7.2			Mandatory
HasComponent	Method	SetMachSpeed		Defined in section 6.7.3			Mandatory
HasComponent	Method	SetProduct		Defined in section 6.7.4			Mandatory
HasComponent	Method	SetParameter		Defined in section 6.7.17			Mandatory
HasComponent	Method	RemoteCommand		Defined in section 6.7.15			Optional
HasComponent	Method	SetInterlock		Defined in section 6.7.16			Optional

TagID – provide an additional field in which an associated name (third party cross reference or other string) can be stored. It can also be an additional name used to identify this PackML System.

PackMLVersion – provides the version of the supported OMAC PackML

Admin provides administrative functionality required for the PackML OPC UA server. It is defined in section 6.3.4. The administrative functionality exposed by this Object should be restricted to only users with administrative rights.

Status provides the status information required for a PackML OPC UA Server. It is defined in section 6.3.3.

SetUnitMode method allows an OPC UA Client to change the mode of the machine. The available modes are part of the supported Modes and a Client can pass any of the values listed. The Method may return an error if the requested mode is not allowed based on either the current mode of the machine or the state of the machine. For additional details see the definition of the SetUnitMode Method in 6.7.2

SetMachSpeed Method allows a Client to change the machine speed.

SetProduct Method allows a Client to change the product(s) and the ProcessVariables and Ingredients. For additional details see the definition of SetProduct Method in 6.7.4 .

SetParameter Method allows a Client to set the parameters for the machine. For additional details see the definition of SetParameter Method in 6.7.17.

RemoteCommand Method allows a Client to send a command to the UA Server that is to be passed to the PackML Server and or upstream or downstream Servers. Parameters sent to the Remote system are typically used in the EXECUTE and STARTING states for a production task. With the restriction that RemoteCommand Parameter Values are limited to REAL values. For additional details see the definition of the RemoteCommand Method in 6.7.15

SetInterlock method allows a Client to set one of the interlocks associated with the system. For additional details see the definition of the SetInterlock Method in 6.7.16

The PackMLStatusObjectType defines an ObjectType that is used to group all of the status information that is part of the PackML information model. It is illustrated in Figure 12

Figure 12 - PackMLStatusObjectType Overview

Table 4 formally defines the PackMLStatusObjectType.

Table 4 – PackMLStatusObjectType Definition

Attribute	Value
BrowseName	PackMLStatusObjectType
IsAbstract	False
Reference	Node Class	BrowseName	DataType	TypeDefinition	ModellingRule	RW
Subtype of the BaseObjectType from OPC 10000-5.
HasComponent	Variable	UnitModeRequested	Boolean	BaseDataVariableType	Optional	R
HasProperty	Variable	UnitSupportedModes	NodeId	PropertyType	Mandatory	R
HasComponent	Variable	UnitModeCurrent	Enumeration	BaseDataVariableType	Mandatory	R
HasComponent	Variable	UnitModeChangeInProcess	Boolean	BaseDataVariableType	Optional	R
HasComponent	Variable	StateRequested	Int32	BaseDataVariableType	Optional	R
HasComponent	Variable	StateChangeInProcess	Boolean	BaseDataVariableType	Optional	R
HasComponent	Variable	MachSpeed	Float	AnalogItemType	Mandatory	R
HasComponent	Variable	CurMachSpeed	Float	AnalogItemType	Mandatory	R
HasComponent	Variable	EquipmentBlocked	Boolean	BaseDataVariableType	Mandatory	R
HasComponent	Variable	EquipmentStarved	Boolean	BaseDataVariableType	Mandatory	R
HasComponent	Variable	MaterialInterlocked	Boolean	BaseDataVariableType	Optional	R
HasInterlock	Variable	MaterialInterlock	Boolean[]	BaseDataVariableType	Optional	R
HasComponent	Variable	Parameter	PackMLDescriptorDataType[]	BaseDataVariableType	Optional	R
HasComponent	Variable	RemoteParameter	PackMLRemoteInterfaceDataType[]	BaseDataVariableType	Optional	R
HasComponent	Variable	Product	PackMLProductDataType[]	BaseDataVariableType	Optional	R

In OPC UA defined StateMachines, a mandatory Variable CurrentState provides the current state of the StateMachine, which is the current state of the PackML device. CurrentState is defined in OPC 10000-5.

UnitModeRequested - If TRUE, indicates that a unit mode change was requested, reflects the status of the Command UnitModeRequested.

UnitSupportedModes – provides the NodeId of the enumeration DataType that describes the available modes for this PackML instance. A Server might have more than one of these instances; each instance might expose a different set of available modes and thus have a different enumeration.

UnitModeCurrent - is used to display the current mode of the instance of this type. The DataType is Enumeration which is abstract, but an instance shall be assigned a concrete enumeration, which corresponds to the enumeration listed in UnitSupportedModes.

UnitModeChangeInProcess – a flag that indicates a unit change has been requested and is in progress

StateRequested - This value is used for state transition checking, to ensure that transitions to a target state can be achieved. The target state, StateRequested, is a numerical value corresponding to a state in the base state model (shown above).

StateChangeInProcess – a flag that indicates that a state change has been requested and is in progress. The StateMachine will report the current state.

MachSpeed - Setpoint speed of the unit.

CurMachSpeed - Current speed of the unit.

Equipment Blocked - If TRUE, then processing is suspended because downstream equipment is unable to receive material (e.g. downstream buffer is full)

Equipment Starved - If TRUE, then processing is suspended because upstream equipment is unable to send material.

MaterialInterlocked – a flag that indicates this machine is interlocked. It is a summary of the interlock variable that is associated with this machine.

MaterialInterlock - this is an array and describes the status of the materials that are ready for processing. It is comprised of a series of Boolean with 1 equaling readyor not low, 0 equaling not ready or low. Each bit represents a different user material.

Parameter – Current parameters used in the production job. This reflects the last parameter sent via the SetParameter Method.

RemoteParameter – the last remote parameter that were sent to the machine. This is optional variable is provided only if sending remote parameters are supported, the RemoteCommand Method is provided this variable shall also be provided. For additional details see the RemoteCommand Method definition in 6.7.15.

Product – provides a list of the products supported by this machine. The array is typically needed for machines that run multiple products. It defines the IDs of the products and process & process variables associated with the product. The product data can come from either a local HMI or remote systems and are used to process the product on the unit machine.

The PackMLAdminObjectType defines an ObjectType that is used to group all of the Admin information that is part of the PackML information model. It is illustrated in Figure 13.

Figure 13 - PackMLAdminObjectType Overview

Table 5 formally defines the PackMLAdminObjectType.

Table 5 – PackMLAdminObjectType Definition

Attribute	Value
BrowseName	PackMLAdminObjectType
IsAbstract	False
Reference	Node Class	BrowseName	DataType	TypeDefinition	ModelingRule	RW
Subtype of the BaseObjectType from OPC 10000-5.
HasComponent	Variable	Parameter	PackMLDescriptorDataType[]	BaseDataVariableType	Optional	R
HasAlarm	Variable	Alarm	PackMLAlarmDataType[]	BaseDataVariableType	Optional	R
HasComponent	Variable	AlarmExtent	Int32	BaseDataVariableType	Optional	R
HasAlarmHistory	Variable	AlarmHistory	PackMLAlarmDataType[]	BaseDataVariableType	Optional	R
HasComponent	Variable	AlarmHistoryExtent	Int32	BaseDataVariableType	Optional	R
HasWarning	Variable	Warning	PackMLAlarmDataType[]	BaseDataVariableType	Optional	R
HasComponent	Variable	WarningExtent	Int32	BaseDataVariableType	Optional	R
HasStopReason	Variable	StopReason	PackMLAlarmDataType	BaseDataVariableType	Optional	R
HasComponent	Variable	StopReasonExtent	Int32	BaseDataVariableType	Optional	R
HasComponent	Variable	ModeCurrentTime	Int32[]	BaseDataVariableType	Optional	R
HasComponent	Variable	ModeCumulativeTime	Int32[]	BaseDataVariableType	Optional	R
HasComponent	Variable	StateCurrentTime	Int32[][]	BaseDataVariableType	Optional	R
HasComponent	Variable	StateCumulativeTime	Int32[][]	BaseDataVariableType	Optional	R
HasComponent	Variable	ProdConsumedCount	PackMLCountDataType []	BaseDataVariableType	Optional	R
HasComponent	Variable	ProdProcessedCount	PackMLCountDataType []	BaseDataVariableType	Optional	R
HasComponent	Variable	ProdDefectiveCount	PackMLCountDataType []	BaseDataVariableType	Optional	R
HasComponent	Variable	AccTimeSinceReset	Int32	BaseDataVariableType	Optional	R
HasComponent	Variable	MachDesignSpeed	Float	BaseDataVariableType	Optional	R

Parameter - The parameter tags associated with the local interface are typically used as parameters that are displayed or used on the unit locally, for example from an HMI. These parameters can be used to display any quality, alarm, or machine downtime parameter. The Parameters are typically limited to parameters related the unit. The length of the array is the maximum number of parameters needed.

Alarm - Alarm Events (trigger, value, message, category,…). The alarm tags associated to the local interface are typically used as parameters that are displayed or used on the unit locally, for example from an HMI. These alarm parameters can be used to display any alarm, or machine downtime cause that is currently occurring in the system. The alarms are typically limited to the machine unit. Each machine can define as many alarms as are required for the machine.

AlarmExtent - Defines the maximum number of alarms available, for the machine annunciation or reporting

AlarmHistory - These alarm history parameters can be used to display any alarm history, or machine downtime cause.

AlarmHistoryExtend - associated with the maximum number of alarms needed to be archived or tagged as alarm history for the machine.

Warning - Array of warning information Events. Warnings are general events that do not cause the machine to stop, but may require operator action because a stoppage may be imminent. Warning elements have the same structure as Stop Reason elements.

WarningExtent - Defines the maximum number of warning elements available.

StopReason - A structure for the stop reason Event (similar to Alarms) which define the possible stop reasons (trigger, value, message, category). Stop Reason is typically used for “First Out Fault” Reporting and Other Stoppage Events. The stop reason is the first event captured during an abort, held, suspended or stop event.

StopReasonExtent - Defines the maximum number of stop reason elements or available.

ModeCurrentTime - The current amount of time, in seconds, that the machine has been in each mode. The array index for a mode is the Unit mode value. The values roll over to 0 at 2,147,483,647.

ModeCumulativeTime - The cumulative amount of time, in seconds, that the machine has been in each mode. The array index for a mode is the Unit mode value. The value is the cumulative elapsed time the machine has spent in each mode since its timers and counters were reset. The values roll over to 0 at 2,147,483,647.

StateCurrentTime - The current amount of time, in seconds, that the machine has been in each state for each mode. The first array index for is the Unit mode value, the second array index is the state value.. The values roll over to 0 at 2,147,483,647.

StateCumulativeTime - The cumulative amount of time, in seconds, that the machine has been in each state for each mode. The first array index for is the Unit mode value, the second array index is the state value. The value is the cumulative elapsed time the machine has spent in each mode and state since its timers and counters were reset. The values roll over to 0 at 2,147,483,647

ProdConsumedCount - Represents the material used/consumed in the production machine. An example of tag usage would be the number of bags consumed in a filler, or bagger packaging machine, or the amount of linear length used, or the number caps used. This tag can be used locally or remotely if needed. The extent of the array is typically limited to the number of raw materials needed to be counted. The array is typically used for unit machines that run multiple raw materials.

ProdProcessedCount - Represents the products processed in the production machine. An example of tag usage would be the number of products that were made, including all good and defective products. The structure of the ProdProcessedCount is the same as the ProdConsumedCount. The length of the array is typically limited to the number of products that need to be counted. The number of products processed minus the defective count is the number of non-defective products made by the machine. The array index of # = 0 should be reserved for the count of the number of units from the primary production stream.

ProdDefectiveCount - Represents the products marked as defective in the production machine. The structure of the ProdDefectiveCount is the same as the ProdConsumedCount. The length of the array is typically limited to the number of products that need to be counted. The number of products processed minus the defective count is the number of non-defective products made by the machine. The array index of # = 0 should be reserved for the count of the number of units from the primary production stream.

AccTimeSinceReset - Represents the amount of time, in seconds, since the last reset of all counters as triggered. Counters that are reset are:

•UnitName.Admin.ModeCurrentTime[#]

•UnitName.Admin.ModeCumulativeTime[#]

•UnitName.Admin.StateCurrentTime[#,#]

•UnitName.Admin.StateCumulativeTime[#,#]

•UnitName.Admin.ProdConsumedCount[#].Count

•UnitName.Admin.ProdProcessedCount[#].Count

•UnitName.Admin.ProdDefectiveCount[#].Count

•UnitName.Admin.AccTimeSinceReset

MachDesignSpeed - Represents the maximum design speed of the machine in primary packages per minute for the package configuration being run. This speed is NOT the maximum speed as specified by the manufacturer, but rather the speed of the machine is designed to run in its installed environment.

The Figure 14 provides an overview of the StateMachines that are part of the model.

Figure 14 - PackML StateMachines Overview

A key point in PackML StateMachines is that all of the StateMachines defined in PackML shall require that the optional AvailableTransitions and AvailableStates component of the FiniteStateMachineType be provided on all instance of the StateMachine. This allows Clients to understand the available States and Transitions for the given instance of the StateMachine. A StateMachine may restrict the States and Transition that are currently available. The following figure provides an overview of the PackML States. The Stopped State is commonly the initial sub-state that will be the starting point for the Cleared parent state. The Running State commonly will use the Resetting State as the initial state, but not all instance of the Running State sub-state model will include Resetting, so no initial state is defined for the Running State. The proposed valid initial States for this model are the Idle or Resetting States. This is Server dependant. The initial state for the system is Aborted. Alternative it could be Cleared as parent state with the proposal of Stopped as initial sub state. Figure 15 - PackML States provide an overview of the states and transitions in the StateMachine. The model refers to the PackML state model Version 2015. The dashed lines for the Hold transitions are optional extensions of the state model

Figure 15 - PackML States

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.

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

The PackMLMachineStateMachineType defines the machine level state machine. It is illustrated in Figure 17.

The TR-88 specification does not define an initial State for this StateMachine, but typically the state machine uses Stopped State as an initial State. Annex B provides recommended display names for the various states.

Figure 17 - PackMLMachineStateMachineType illustration

Table 8 defines the PackMLMachineStateMachineType. StateTypes and TransitionTypes only exist in the type system, thus they do not have a modelling rule.

Table 8 – PackMLMachineStateMachineType Definition

Attribute	Value
BrowseName	PackMLMachineStateMachineType
IsAbstract	False
Reference	Node Class	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the FiniteStateMachineType from OPC 10000-5.
HasComponent	Variable	0:AvailableTransitions	NodeId[]	BaseDataVariableType	Mandatory
HasComponent	Variable	0:AvailableStates	NodeId[]	BaseDataVariableType	Mandatory
HasComponent	Object	Stopped		StateType
HasComponent	Object	Stopping		StateType
HasComponent	Object	Clearing		StateType
HasComponent	Object	Running		StateType
HasComponent	Object	ExecuteState		PackMLExecuteStateMachineType	Mandatory
HasComponent	Object	StoppingToStopped		TransitionType
HasComponent	Object	ClearingToStopped		TransitionType
HasComponent	Object	StoppedToRunning		TransitionType
HasComponent	Object	RunningToStopping		TransitionType
HasComponent	Method	Stop	Defined in 6.7.7		Optional
HasComponent	Method	Reset	Defined in 6.7.8		Optional

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

Stopped - The machine is powered and stationary after completing the STOPPING state. All communications with other systems are functioning (if applicable). The value of this StateType is 2

Stopping - This state executes the logic which brings the machine to a controlled stop as reflected by the STOPPED state. The value of this StateType is 7.

Clearing - Initiated by a state command to clear faults that may have occurred when ABORTING, and are present in the ABORTED state. The value of this StateType is 1.

Running – the State that allows the ExecuteState machine to become active, enabling sub-states provided by this StateMachine. The value of this StateType is 18.

ExecuteState – StateMachine that provides additional sub states.

Stop – A Method to trigger a change of state to Stopping. This will affect all sub-states in Run state. Defined in 6.7.7

Reset – A Method to trigger a change of state to Running, enabling all of the sub-states of Running and the respective Methods that they expose. Defined in 6.7.8

The transitions are defined in Table 9.

Table 9 – PackMLMachineStateMachineType Additional References

Source Path	Reference Type	Is Forward	Target Path
StoppedToRunning	FromState	True	Stopped
	ToState	True	Running
	HasCause	True	Reset
StoppingToStopped	FromState	True	Stopping
	ToState	True	Stopped
ClearingToStopped	FromState	True	Clearing
	ToState	True	Stopped
RunningToStopping	FromState	True	Running
	ToState	True	Stopping
	HasCause	True	Stop

The PackMLExecuteStateMachineType provides all of the base states defined in PackML. It is illustrated in Figure 18. The TR-88 specification does not define an initial State for this StateMachine, but typically the state machine use either the Idle or Resetting State as an initial State. Annex B provide recommended display names for the various states.

Figure 18 – PackMLExecuteStateMachineType illustration

The PackMLExecuteStateMachineType is defined in Table 10. StateTypes and TransitionTypes only exist in the type system, thus they do not have a modelling rule.

Table 10 – PackMLExecuteStateMachineType Definition

Attribute	Value
BrowseName	PackMLExecuteStateMachineType
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	Resetting		StateType
HasComponent	Object	Idle		StateType
HasComponent	Object	Starting		StateType
HasComponent	Object	Suspending		StateType
HasComponent	Object	Suspended		StateType
HasComponent	Object	Unsuspending		StateType
HasComponent	Object	Holding		StateType
HasComponent	Object	Held		StateType
HasComponent	Object	Unholding		StateType
HasComponent	Object	Execute		StateType
HasComponent	Object	Completing		StateType
HasComponent	Object	Complete		StateType
HasComponent	Object	ResettingToIdle		TransitionType
HasComponent	Object	IdleToStarting		TransitionType
HasComponent	Object	StartingToExecute		TransitionType
HasComponent	Object	ExecuteToSuspending		TransitionType
HasComponent	Object	SuspendingToSuspended		TransitionType
HasComponent	Object	SuspendedToUnsuspending		TransitionType
HasComponent	Object	UnsuspendingToExecute		TransitionType
HasComponent	Object	ExecuteToHolding		TransitionType
HasComponent	Object	HoldingToHeld		TransitionType
HasComponent	Object	HeldToUnholding		TransitionType
HasComponent	Object	UnholdingToExecute		TransitionType
HasComponent	Object	ExecuteToCompleting		TransitionType
HasComponent	Object	CompletingToComplete		TransitionType
HasComponent	Object	CompleteToResetting		TransitionType
HasComponent	Object	StartingToHolding		TransitionType
HasComponent	Object	UnsuspendingToHolding		TransitionType
HasComponent	Object	SuspendedToHolding		TransitionType
HasComponent	Object	SuspendingToHolding		TransitionType
HasComponent	Object	UnholdingToHolding		TransitionType
HasComponent	Method	Reset	Defined in Clause 6.7.8		Optional
HasComponent	Method	ToComplete	Defined in Clause 6.7.9		Optional
HasComponent	Method	Start	Defined in Clause 6.7.10		Optional
HasComponent	Method	Unhold	Defined in Clause 6.7.11		Optional
HasComponent	Method	Suspend	Defined in Clause 6.7.12		Optional
HasComponent	Method	Hold	Defined in Clause 6.7.14		Optional
HasComponent	Method	Unsuspend	Defined in Clause 6.7.13		Optional

*Not all transitions defined in ANSI/ISA - TR88.00.02 - 2015. Following additional transitions in the object prepared for potential future extensions in TR88: StartingToHolding, UnsuspendingToHolding, SuspendedToHolding, SuspendingToHolding, UnholdingToHolding.

This FiniteStateMachine supports multiple Active states. It also supports 19 Transitions and a Method for transition between states.

Resetting: In response to a Reset command, the unit/machine will transition to Resetting from either Stopped or Complete. In this state the unit/machine attempts to clear any standing errors or stop causes. If successful, the unit/machine transitions to Idle. No hazardous motion should happen in this state. The value of this StateType is 15

Idle: The unit/machine is in an error-free state, waiting to start. The unit/machine transitions automatically to Idle after all steps necessary for Resetting have been completed. All conditions achieved during Resetting are maintained. A Start command will transition the unit/machine from Idle to Starting. The value of this StateType is 4.

Starting: The unit/machine completes all steps necessary to begin execution of the active machine mode. A Start command will cause the unit/machine to transition from Idle to Starting. The unit/machine will transition automatically from Starting to Execute once all required steps have been completed. The value of this StateType is 3.

Suspending: The unit/machine will transition from Execute to Suspending if conditions external to the unit/machine require a pause in production. Such conditions include faults to upstream or downstream equipment. The decision to Suspend may be made be a supervisory system monitoring the production line conditions or by unit/machine sensors detecting downstream blockages or upstream product scarcity. (In the former case, the unit/machine is 'blocked”; in the latter case, the unit/machine is “starved”) After all steps required to suspend the machine have been completed, the unit/machine will automatically transition to Suspended state. The value of this StateType is 13.

Suspended: The unit/machine is paused, waiting for external process conditions to clear. In this state, the unit/machine shall not produce product, but may, if required, dry-cycle. Once external conditions have returned to normal, the unit/machine will transition to Unsuspending, typically without operator intervention. The value of this StateType is 5.

Unsuspending: After all external process conditions that caused the unit/machine to suspend have cleared, the unit/machine completes all steps required to resume execution of the active machine mode. Once all required actions to unsuspend the unit/machine have been completed, the unit/machine will automatically transition to Execute state. The value of this StateType is 14.

Holding: The unit/machine will transition from Execute to Holding if conditions internal to the unit/machine require a pause in production. Such conditions would include low levels on materials required for production or other minor issues requiring operator service, for example. The decision to hold may be made automatically by the unit/machine itself or by an operator. After all steps required to hold the machine have been completed, the unit/machine will transition automatically to Held state. The value of this StateType is 10.

Held: The unit/machine is paused, waiting for internal process conditions to clear. In this state, the unit/machine shall not produce product, though it may, if required, dry-cycle. A transition to Unholding will occur once internal machine conditions have cleared or if the Unhold command is initiated by an operator. The value of this StateType is 11.

Unholding: After all internal process conditions that caused the unit/machine to hold have cleared, the unit/machine completes all steps required to resume execution of the active machine mode. Once all required actions to unhold the machine have been completed, the unit/machine will transition automatically to Execute state. The value of this StateType is 12.

Execute: If the unit/machine is actively carrying out the behaviour or activity defined by the selected mode, then the machine is in Execute state. If the unit/machine is in production mode, for example, this means that the machine is producing product. The value of this StateType is 6.

Completing: Once the process associated with the current mode has reached a defined threshold (e.g. the required number of products for the current job have been produced), the unit/machine transitions from Execute to Completing. In this state all steps necessary to shut down the current process are carried out. The machine then transitions automatically to Complete state. The value of this StateType is 16.

Complete: Complete indicates the process associated with the active mode has come to its defined end. The unit/machine will wait in this state until a Reset command is issued (in which case it will transition to Resetting), or until the unit/machine is Stopped or Aborted. The value of this StateType is 17.

The Transitions are described in Table 11. This FiniteStateMachine also supports six Methods, for transitioning between states. This StateMachine includes transition to Holding from Unholding, Starting, Unsuspending, Suspended, Suspending, all of which are extension to the ISA-TR88.00.02-2015 specification.

Table 11 – PackMLExecuteStateMachineType Additional References

Source Path	Reference Type	Is Forward	Target Path
ResettingToIdle	FromState	True	Resetting
	ToState	True	Idle
IdleToStarting	FromState	True	Idle
	ToState	True	Starting
	HasCause	True	Start
StartingToExecute	FromState	True	Starting
	ToState	True	Execute
ExecuteToSuspending	FromState	True	Execute
	ToState	True	Suspending
	HasCause	True	Suspend
SuspendingToSuspended	FromState	True	Suspending
	ToState	True	Suspended
SuspendedToUnsuspending	FromState	True	Suspended
	ToState	True	Unsuspending
	HasCause	True	Unsuspend
UnsuspendingToExecute	FromState	True	Unsuspending
	ToState	True	Execute
ExecuteToHolding	FromState	True	Execute
	ToState	True	Holding
	HasCause	True	Hold
StartingToHolding	FromState	True	Starting
	ToState	True	Holding
	HasCause	True	Hold
SuspendingToHolding	FromState	True	Suspending
	ToState	True	Holding
	HasCause	True	Hold
SuspendedToHolding	FromState	True	Suspended
	ToState	True	Holding
	HasCause	True	Hold
UnsuspendingToHolding	FromState	True	Unsuspending
	ToState	True	Holding
	HasCause	True	Hold
UnholdingToHolding	FromState	True	Unholding
	ToState	True	Holding
	HasCause	True	Hold
HoldingToHeld	FromState	True	Holding
	ToState	True	Held
HeldToUnholding	FromState	True	Held
	ToState	True	Unholding
	HasCause	True	Unhold
UnholdingToExecute	FromState	True	Unholding
	ToState	True	Execute
ExecuteToCompleting	FromState	True	Execute
	ToState	True	Completing
	HasCause	True	ToComplete
CompletingToComplete	FromState	True	Completing
	ToState	True	Complete
CompleteToResetting	FromState	True	Complete
	ToState	True	Resetting
	HasCause	True	Reset

*Not all transitions defined in ANSI/ISA - TR88.00.02 - 2015. Following additional transitions in the object prepared for potential future extensions in TR88: StartingToHolding, UnsuspendingToHolding, SuspendedToHolding, SuspendingToHolding, UnholdingToHolding.