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.