Problem

I/O Variables mapped from an I/O device do not change value.

Before SP17

values are greyed


From SP17

Since SP17, some clearer hints are given:

  • the value is shown as "not updated"
  • a tooltip explains why

Solution

By default, a variable is shown with the actual value only if the variable is used in a task.

Your options are either:

  • use in your code, those IO variables you are interested in
  • Set the "Always update variables" setting for this IO to "Enabled 1 (use bus cycle if not used in any task)"
  • Set the "Always update variables" setting for this IO to Use parent device setting, and set "Enabled 1 (use bus cycle if not used in any task)" in a parent device.


Note

The "Always update variables" setting is on the "<Name> I/O Mapping" tab for most devices.

For the PLC Controller devices, it is on the "PLC Settings" tab.

Result