Corrected from:
Response of the new version:
The values of variables declared as VAR_IN_OUT variables of a function block can be recorded in a trace.
The following message appears when starting a trace in the PLC Designer:
Invalid trace variable (Invalid expression (No external access to 'VAR_IN_OUT' parameter 'Variable name' of 'POU name'))
When does this behaviour occur?
The above message appears if you want to record a VAR_IN_OUT variable of a function block in a trace.
Which products are affected?
PLC Designer from V3.0
Short-term measures:
Use the variable assigned to the VAR_IN_OUT variable outside the function block for recording in a trace.
Evaluation/recommendations:
VAR_IN_OUT variables cannot be recorded in a trace. An applicative solution is described under 'Short-term measures'.
