AccessOPCUAVariable (Activity)
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| Configure OPC UA Variable | |
|---|---|
| Name | AccessOPCUAVariable |
| Purpose | Read or write a single OPC UA variable |
| Category | UBIK OPC UA Interface |
| Returns | True if successful |
| Version | 2.4.1+ |
The AccessOPCUAVariable reads or writes a single OPC UA Variable that was previously configured within an OPC Connection.
Contents
Arguments
| Argument | Type | Direction | Purpose |
|---|---|---|---|
| Variable | OpcUaVariable | In | The variable to read or write as produced by a Scope activity. |
| Value | object | In | The value to write to the variable. If null, the variable will be read. |
| Connection | OpcUaServerConnection | In | If the activity is not embedded with an Scope activity, a valid connection has to be specified. |
| Quality | OpcUaQuality | Out | The quality of the accessed value as delivered by the OPC source |
| Result | Boolean | Out | True if successful, false if failed |
Usage
This activity is used to open a preconfigured OPC Connection. It is a nestable activity, which means it can host any amount of sub-activities that will be processed sequentially. The hosted activities are typically AccessOPCUAVariable activities, either as direct children but also wrapped within looping activities like ForEach or While. When all child activities are processed the OPC connection will be closed again.
Example
The CreateOPCUAScope activity, as used in the larger example "Read value from OPC variable":
