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OPC UA Write

Write data to OPC UA server

Since R2024a

  • OPC UA Write Block

Industrial Communication Toolbox / OPC Unified Architecture


The OPC UA Write block writes data to one or more nodes on an OPC Unified Architecture (UA) server. The write operation takes place synchronously at a specified sample time.

Each input port writes data to a corresponding node in the Nodes list of the OPC UA Write block. Each node can accept data of different data types.


You need a license for both Industrial Communication Toolbox™ and Simulink® software to use this block.


You must connect at least one OPC UA server to use the OPC UA Read block. You can create an OPC UA client using the OPC Configuration pane in the Configuration Parameters dialog box of the model. You must add at least one OPC UA Read or OPC UA Write block in the model to enable this pane. For more information, see Configure OPC UA Client in Simulink.



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Values to write to OPC UA server nodes. The number of input ports corresponds to the number of nodes you select in the Nodes parameter.

For more information on the data types supported at the Value port, see OPC UA Server Data Types.


To enable this port, specify one or more nodes in the Nodes parameter.

Data Types: Boolean | single | double | datetime | duration | int8 | int16 | int32 | int64 | uint8 | uint8 vector | uint16 | uint32 | uint64 | struct | char vector


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Select the OPC UA client associated with the block.

  • To add the required clients using the OPC configuration pane, click Configure servers. For more information, see Configure OPC UA Client in Simulink.

  • To update the block to the latest OPC configuration, click Refresh.

Programmatic Use

Block Parameter: ServerList
Type: string | character vector

Select nodes to write to the specified server.

  • To add variable type nodes, click Add. This action opens the Browse Name Space dialog box for the selected OPC UA server. Using this browser, you can select the nodes that you want to add to the Nodes list.

  • To delete selected nodes, click Delete.

  • To change the order of the selected nodes in the list, click Move Up or Move Down. The serial number of the nodes determines the order in which the block inputs the signals at the input ports.

Programmatic Use

Block Parameter: NodeList
Type: string | character vector

Define the sample time of the block in seconds. The block writes the data to the server synchronously at the specified sample time. You can specify 0 for continuous mode, or -1 to inherit the sample time of the block connected to the input of the OPC UA Write block. For more information, see Specify Sample Time (Simulink).

Programmatic Use

Block Parameter: SampleTime
Type: string | character vector
Values: numeric
Default: '-1'

Version History

Introduced in R2024a