Last modified on 20 November 2014, at 08:18

AccessOPCUAVariable (Activity)

Revision as of 08:18, 20 November 2014 by JKN (Talk | contribs) (Usage)

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.

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 read or write a value of a single OPC variable within an OPC Scope. if Value is supplied with null, it will read the value of the variable. If Value is supplied with something else than null, it will attempt to write it to the variable. If it is used outside of a scope activity, it has to be supplied with a valid OPC connection object as produced by an OPC connection somewhere else in the workflow.

Example

The CreateOPCUAScope activity, as used in the larger example "Read value from OPC variable":

UI Activity CreateOPCUAConnection Example.png

See also