Node-RED is a low-code programming tool for event-driven applications. To integrate data points of the NETx Server we suggest to use the OPC UA server interface.

Installation

• Follow installation instructions of Node-RED to install the tool.

• Follow installation instruction of OPC UA to allow data access by Node-RED.

Configuration

After the installation, restart the Core Studio and activate the driver in Modules > OPCUA > Server configuration:

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Restart the NETx Server and monitor the log messages for the OPC UA endpoints:

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Example

The attached  is a Node-RED flow that contains examples to

• actively read a server item

• write a server item

• subscribe to a server item.

The related server item is always NETx\VAR\Numeric\Item001.

Node-RED setup

• In the Node-RED UI, import the flow:

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• Double-click the read node. In the OpcUa-Client node configuration, click the Edit button of the Endpoint field:

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• Set the correct endpoint URL and provide credentials of a Web Manager user (default is admin / changeme).

• Click the Deploy button on the upper right.

• Open the debug console and clear all messages:

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Read

• Switch to the Core Studio and set the value of server item NETx\VAR\Numeric\Item001 to 123.

• Back in Node-RED, click the Test node beneath the active read note: The data point is actively read from the server and its value is logged:

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Write

• Click any of the nodes beneath the write note and watch the data point in the Core Studio as it assumes the respective values of 100 and 200.
  

Subscribe

• Click the Test node beneath the subscribe note to subscribe to value changes.

• Change the value of the server item in the Core Studio and monitor the Node-RED debug console for receiving the respective values: