# Creating Monitoring Variables

Once PROFINET communication is set up properly, create the monitoring variables. To prepare for the procedure, first open the applicable In-Sight 3800 Vision System PROFINET IO Module Reference Table. This reference table is for checking which signals you need for the configured application. You can add the necessary signals to the symbols in TIA Portal, and you can name the signals to monitor them easily.

Perform the following steps to create the monitoring variables:

1. On the Project tree pane, go to the following location:

   Vision System => PLC_1 [CPU 1211C DC/DC/DC] => PLC tags

2. Double-click the Add new tag table. This adds Tag table_1. Double-click the Tag table_1 to open it.

3. Open the Device overview tab on the top of the screen to check the Q and I addresses to use for each module.

4. Open Tag table_1, and fill it according to the contents of the Device overview tab, then save the project. This is necessary to see the names of the variables when they are monitored.

5. On the Project tree pane, go to the following location:

   Vision System => PLC_1 [CPU 1211C DC/DC/DC] => Watch and force tables

6. Double-click the Add new watch table. This adds Watch table_1. Double-click the Watch table_1 to open it.

7. Fill the Address column as you can see in the table below. Cognex recommends filling the Name column first, as the Address and Display format columns are filled automatically when selected, according to the values configured in Step 4. Save these values for future use.

8. Click the Monitor all icon, so that the Monitor value column is updated cyclically, and the changes coming from the vision system can be monitored. To modify a variable in this case, type the new value in the Modify value column, and then click the Modify all selected values once and now icon.