Add and configure an OPC DA variable

An OPC DA variable item is an item that you add to an OPC DA group. It represents a variable tag or data point on an OPC DA server. A variable stores a scalar value that is compatible with an OLE DB variable value, which permits the use of OPC DA variables and OLE DB variables in the same expression. AVEVA™ Production Management updates OPC DA variables when the OPC DA server sends changes through.

You can add multiple variables to a project. Add a separate OpcVariable item to the Project Explorer for each variable tag on the OPC DA server that you want to use. You can map multiple OpcVariable items to the same variable tag on the OPC DA server.

Use the following procedure to add one variable at a time. To import one or more variables simultaneously from an OPC DA server, use the OPC DA variables configuration tool.

Note: If you use the following procedure, rather than using the OPC DA variables configuration tool, AVEVA Production Management initially gives the OpcItemID property and the Name property of the variable the same value. If you do not change the value of the OpcItemID property; that is, it still contains the same value as the Name property, changes to the Name property cause AVEVA Production Management to give the OpcItemID property the same value.

Prerequisite

Add and configure an OPC DA group.

To add an OPC DA variable

1. In the Project Explorer, right-click the group, and then click Add Variable. An OpcVariable item appears.

   

2. Rename the item with a meaningful name.

3. Configure the properties. For guidance in configuring the properties, see OPC DA connector variable properties.

Related topics

• Add and configure an OPC DA data source

• Add and configure an OPC DA data connection

• Use the Project Explorer

• About the OPC DA variables configuration tool