When configuring an I/O Driver, users can perform a test procedure to check whether its values are correct and being updated with no problems. When clicking an I/O Driver, the Activate Driver option can be used.

Thus, the specified I/O Driver is loaded and its variable values can be viewed in each Tag's Value field on its design View. In case there is a Tag with its AllowRead property set to False, or even with no value to be reported, this row appears in gray.

When a Tag contains communication errors, its row turns into red, and in case it displays no problems, its row turns into blue. To interrupt this monitoring process, right-click an I/O Driver again and select the Deactivate Driver option.