7.1.2 LADSDeviceStateMachineType ObjectType Definition

7.1.2.1 Overview

The LADSDeviceStateMachineType state machine represents the Device’s current state. It is inspired by the AnalyserDeviceStateMachineType from the Analyzer Devices Specification.

The LADSDeviceStateMachine is depicted in Figure 15

Figure 15 – LADSDeviceStateMachine

The LADSDeviceStateMachineType is formally defined in Table 17.

Table 17 – LADSDeviceStateMachineType Definition
Attribute Value
BrowseNameLADSDeviceStateMachineType
IsAbstractFalse
References Node Class BrowseName DataType TypeDefinition Other
Subtype of the FiniteStateMachineType defined in OPC 10000-5
0:HasComponentMethodGotoOperateO
0:HasComponentMethodGotoShutdownO
0:HasComponentMethodGotoSleepO
0:HasComponentObjectOperateStateType
0:HasComponentObjectOperateToShutdownTransitionType
0:HasComponentObjectOperateToSleepTransitionType
0:HasComponentObjectInitializationInitialStateType
0:HasComponentObjectInitializationToOperateTransitionType
0:HasComponentObjectShutdownStateType
0:HasComponentObjectSleepStateType
0:HasComponentObjectSleepToOperateTransitionType
Conformance Units
LADS LADSDeviceStateMachineType

There are four Device states, as follows:

Initialization: The Device is in its initializing sequence and cannot perform any other Task.

Operate: The Device is in Operating mode. The LADS Client uses this mode for normal operation: configuration, control, and data collection.

Sleep: The Device is still powered on and its OPC UA Server is still running, but it is not ready to perform any Tasks until it transitions to the Operate state. This state can be used to represent a PowerSave state where a Device may shut down some of its Components, such as the GUI. It can also be used to represent a Sleep state, where a Device is running with minimal services but ready to be triggered to transition into the Operate state.

Shutdown: The Device is in its power-down sequence and cannot perform any other Task. Optionally, there are devices that can be powered off via physical means, especially simpler ones. The electronics are turned off immediately; therefore, such devices do not transition into a Shutdown state.

Note: Shutdown is the state in which the LADS Device waits for the completion of the power down sequence. Its sub-states are out of scope of the LADS specification.

Children of the LADSDeviceStateMachineType have additional References, which are defined in Table 18.

Table 18 – LADSDeviceStateMachineType additional References
SourceBrowsePath Reference Type Is Forward TargetBrowsePath
InitializationToOperate0:FromStateTrueInitialization
0:ToStateTrueOperate
0:HasEffectTrueTransitionEventType
OperateToSleep0:FromStateTrueOperate
0:ToStateTrueSleep
0:HasCauseTrueGotoSleep
0:HasEffectTrueTransitionEventType
SleepToOperate0:FromStateTrueSleep
0:ToStateTrueOperate
0:HasCauseTrueGotoOperate
0:HasEffectTrueTransitionEventType
OperateToShutdown0:FromStateTrueOperate
0:ToStateTrueShutdown
0:HasCauseTrueGotoShutdown
0:HasEffectTrueTransitionEventType

The Component Variables of the LADSDeviceStateMachineType have additional Attributes, as defined in Table 19.

Table 19 – LADSDeviceStateMachineType Attribute Values for Child Nodes
BrowsePath Value Attribute
1
2
3
4
3
4
2
1
7.1.2.2 GotoOperate

The GotoOperate Method is used to set the Device into an operating mode. The signature of this Method is specified below. Table 20 specifies its representation in the AddressSpace.

Signature 

	GotoOperate ()
Table 20 – GotoOperate Method AddressSpace Definition
Attribute Value
BrowseNameGotoOperate
References Node Class BrowseName DataType TypeDefinition ModellingRule
7.1.2.3 GotoShutdown

The GotoShutdown Method is used to shut down the Device. The signature of this Method is specified below. Table 21 specifies its representation in the AddressSpace.

Signature 

	GotoShutdown ()
Table 21 – GotoShutdown Method AddressSpace Definition
Attribute Value
BrowseNameGotoShutdown
References Node Class BrowseName DataType TypeDefinition ModellingRule
7.1.2.4 GotoSleep

The GotoSleep Method is used to set the Device to Sleep. The signature of this Method is specified below. Table 22 specifies its representation in the AddressSpace.

Signature 

	GotoSleep ()
Table 22 – GotoSleep Method AddressSpace Definition
Attribute Value
BrowseNameGotoSleep
References Node Class BrowseName DataType TypeDefinition ModellingRule