Chapter 13. OPC to InTouch

Table of Contents

13.1. Getting data into InTouch
13.2. Getting data out of InTouch
13.3. Reading and writing data in both directions
13.4. Error message displayed when starting InTouch WindowViewer

13.1. Getting data into InTouch

The OPC DataHub can act as a DDE server to your InTouch application. To access data from the OPC DataHub you simply need to configure an InTouch Access Name which points to the dho data domain containing the data you are interested in. Then you just associate tagnames in InTouch with corresponding dho point names.

Configuring the OPC DataHub

  1. Right click on the OPC DataHub system-tray icon and choose Properties.
  2. In the Properties window, select DDE .
  3. Ensure that the box Act as a DDE server is checked, and that the name datahub appears in the DDE Service Name area. If not, click the Add... button and add the name datahub.
  4. Click OK to close the Properties window.

Configuring InTouch Access Names

For InTouch to establish the connection to the OPC DataHub you need to set up an Access Name.

  1. In the InTouch WindowMaker program, from the Special menu, select Access Names.
  2. Click the Add button to add a new Access Name.
  3. Enter the information in the Add Access Name window as follows:

    Create a name.

    Node Name

    Can be left blank if the DataHub is running on the same computer as the InTouch application. Otherwise, the name of the node that the DataHub is running on.

    Application Name


    Topic Name

    The DataHub data domain name (in the example above the Access Name would be associated with the DataSim data domain).

    Which protocol to use

    Select DDE.

  4. Click OK to add the new Access name.

This Access Name will be associated with all InTouch tags that receive data from the DataHub.

Configuring InTouch Tag Names

To associate an InTouch tag with a DataHub point, the tag must be defined as an I/O type tag.

Read Only Tagnames 

The image below shows a tagname configuration for a Read Only Write tagname. This means the value can only be read from the DataHub into your InTouch application.

In the Tagname Dictionary window:

  1. Choose one of the I/O types of tagname.
  2. Click the AccessNames button and select the DataHub access name.
  3. In the Item field, enter the name of the corresponding point from the DataSim data domain in the DataHub.
  4. Enter values for Min EU, Max EU, Min EU, and Max Raw.
  5. Click Save, then click Close.

Read/Write Tagnames 

The image below shows a similar tagname configuration for a Read/Write tagname. This allows you to both read and write data back to the DataHub from your InTouch application.