6 PubSub communication parameters ToC Previous Next

6.2 Common configuration parameters ToC Previous Next

6.2.1 PubSubState state machine ToC Previous Next

The PubSubState is used to expose and control the operation of a PubSub component. It is an enumeration of the possible states. The enumeration values are described in Table 1.

Table 1 – PubSubState values

Name Value Description
Disabled 0 The PubSub component is configured but currently disabled.
Paused 1 The PubSub component is enabled but currently paused by a parent component. The parent component is either Disabled or Paused.
Operational 2 The PubSub component is operational.
Error 3 The PubSub component is in an error state.
PreOperational 4 The PubSub component is enabled but currently in the process to execute the steps necessary to enter the Operational state.

Figure 21 depicts the PubSub components that have a PubSub state and their parent-child relationship. State changes of children are based on changes of the parent state. The root of the hierarchy is the PublishSubscribe component.

readme_files/image024.png Figure 21 – PubSub component state dependencies

Figure 22 describes the formal state machine with the possible transitions.

readme_files/image025.png Figure 22 – PubSubState state machine

Table 2 formally defines the transitions of the state machine.

Table 2 – PubSubState state machine

Source State Target State Trigger Description
Disabled Paused The component was successfully enabled but the parent component is in the state Disabled or Paused.
Disabled PreOperational The component was successfully enabled.
Paused Disabled The component was successfully disabled.
Paused PreOperational The state of the parent component changed to Operational.
PreOperational Operational    The component completed the steps necessary to enter the Operational state.If the PubSub component is a DataSetReader, the state shall change to Operational after the first key frame or event DataSetMessage was received.
PreOperational Disabled The component was successfully disabled.
PreOperational Paused The state of the parent component changed to Disabled or Paused.
PreOperational Error There is a pending error situation for the related PubSub component.
Operational Disabled The component was successfully disabled.
Operational Paused The state of the parent component changed to Disabled or Paused.
Operational Error There is a pending error situation for the related PubSub component.
Error Disabled The component was successfully disabled.
Error Paused The state of the parent component changed to Disabled or Paused.
Error Operational The error situation was resolved for the related PubSub component.
Error PreOperational The error situation was resolved for the related PubSub component.

The PubSubState representation in the AddressSpace is defined in Table 3.

Table 3 – PubSubState definition

Attribute Value        
BrowseName PubSubState        
IsAbstract False        
References Node Class BrowseName DataType TypeDefinition Others
Subtype of Enumeration defined in OPC 10000-5          
HasProperty Variable EnumStrings LocalizedText [] PropertyType  
Conformance Units          
PubSub Model Base          

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