Use the IOStatus topic name

You can prepare the IOStatus topic to monitor I/O communication between WindowViewer and an I/O Server. In this example, WindowViewer communicates with the Simulation I/O Server to a PLC defined in the I/O Server with PLC1 as its topic name.

Note: The Simulation Server is a generic DAServer used as a training tool. The Simulation Server is located in the c:\program files\common files\ArchestrA folder.

Monitor the status of I/O communications

1. Open an application in WindowMaker.

2. Open the Tagname Dictionary.

3. Create an I/O discrete tag.

   When you are monitoring a I/O conversation using IOStatus, you must define at least one I/O type tag to the Access Name being monitored.

   

4. Select Access Name to assign the tag to an Access Name definition that defines IOStatus as its topic name.

   

   Notice the PLC1 Access Name definition currently exists.

5. Highlight PLC1 and select Modify.

   

   Finding the Access Name containing the right topic name in this example is easy because the tag and Topic Name are the same.

6. Select Cancel to close the dialog box and return to the initial Access Name dialog box.

7. Select Add.

   The Add Access Name dialog box appears.

   

8. Do the following:

   1. In the Access box, type IOStatus.

   2. In the Application Name box, type View because you are going to monitor the status from WindowViewer.

   3. In the Topic Name box, type IOStatus as the InTouch internal topic.

   4. Select Advise only active items.

9. Select OK to close the dialog box. The initial Access Name dialog box reappears showing your new Access Name, IOStatus, in the list:

   

10. Select Close to close the dialog box and associate the new Access Name with your I/O Discrete tag.

    In the Item box, type the Access Name for the actual topic name that you want to monitor.

    

11. Because your tag is the same as the Topic Name, you can select Use Tagname as Item Name and automatically enter it as the Item.

    Note: When using the built-in topic IOStatus (DDEStatus before InTouch Version 7.0) to monitor an I/O conversation, the name you type in the Access Name box is always also used for the Item.

The Item Name can be a string up to 254 characters. The item name length is calculated as the sum of the Topic Name, Item Name and 1 delimiter character.