OPC-Classic-DARead node

Use the OPC-Classic-DARead node to connect to a OPC Classic DA Server. The sensors in your devices send data to your OPC Classic DA Server. You can use the OPC-Classic-DARead node to retrieve tag data values, these values are then output in TagData XML format.

You can deploy the OPC-Classic-DARead node on Windows only.

The OPC-Classic-DARead node is contained within the Manufacturing drawer of the message flow palette, and is represented in the IBM® Integration Toolkit by the following image:

The OPC-Classic-DARead node is a mid-flow node.

In the Properties view, specify the OPC Classic DA Server that you want to connect to, and the tags for which you want to receive data.

For any tags that you add to the Tags property, the node outputs data in an XML format. To access or update the values under TagData, you must address it with its namespace. For more information, see XML schema.

If you wire the InvalidTags terminal, a message is sent from the InvalidTags terminal that contains information about any tags that could not be read and another message is sent from the Out terminal about any tags that could be read. If you do not wire the InvalidTags terminal and any of the specified tags could not be read, an exception is thrown and no message is sent from the Out terminal.

You can choose to output the message to either the message body, or, if you want to preserve the message, you can output the message to LocalEnvironment.

You can route or transform this data by using the nodes that are in the IBM Integration Toolkit palette. For example, you can publish the data by using an MQTTPublish node, and then subscribe to the data by using an MQTTSubscribe node, see MQTTPublish node and MQTTSubscribe node.

Configure the OPC-Classic-DARead node by modifying the properties.

All mandatory properties for which you must enter a value (properties that do not have a default value defined) are marked with an asterisk in the user interface.

The following tables describe the node properties. The column headed M indicates whether the property is mandatory (a mandatory property is marked with an asterisk if you must enter a value when no default is defined); the column headed C indicates whether the property is configurable (you can change the value when you add the message flow to the broker archive (BAR) file to deploy it).