EnterStepSequenceEventType is an EventType subtype of BaseEventType, defined in OPC 10000-5. This event is to be triggered by the server when in the Entry state the decision is taken that under the current circumstances (superior state, recipe etc.) a step sequence is to be executed and the transition into the first Wait state is initiated. The structure is defined in Figure 34. It is formally defined in Table 120.

Event properties

• Steps: number of steps to expect. If the number of steps is not known, this should be -1. Even if this is a positive value, the client should not rely on it because circumstances occurring during execution of the step model may change the number of steps required, for example a call to the Sync method with a particular mode argument.

Figure 34 – Overview EnterStepSequenceEvent

Table 120 – EnterStepSequenceEventType definition

Attribute	Value
BrowseName	EnterStepSequenceEventType
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseEventType defined in OPC 10000-5
HasProperty	Variable	Steps	Int32	PropertyType	Mandatory

NextStepEventType is an EventType subtype of BaseEventType, defined in OPC 10000-5. This event is to be triggered by the server when in the Step state the decision is reached that under the current circumstances (superior state, recipe, number of steps already taken, parameter of Sync method) another step has to be taken and the state machine must translate to the Wait state. It is formally defined in Table 121

Event properties

• State NodeId
• Running number of the step

Figure 35 – Overview NextStepEvent

Table 121 – NextStepEventType definition

Attribute	Value
BrowseName	NextStepEventType
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseEventType defined in OPC 10000-5
HasProperty	Variable	Step	Int32	PropertyType	Mandatory

LeaveStepSequenceEventType is an EventType subtype of BaseEventType, defined in OPC 10000-5, this event is to be triggered by the server when in the Step state the decision is reached that under the current circumstances (superior state, recipe, number of steps already taken, parameter of Sync method) no further steps have to be taken and the transition into the Exit state is initiated. It is formally defined in Table 122.

Figure 36 – Overview LeaveStepSequenceEventType

Table 122 – LeaveStepSequenceEventType definition

Attribute	Value
BrowseName	LeaveStepSequenceEventType
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseEventType defined in OPC 10000-5