Which products are affected?
ESP-DDS2-x (Global Drive PLC Developer Studio as of version 2.x)
What happens?
The menu item Project>Show reference list indicates where variables are used in the DDS project.
The cross-reference list indicates a write access to a variable inside a POU although this write access has not been programmed into the POU.
When does the problem occur?
If a cross-reference list is created for a variable which has been declared in a POU of the type (FUNCTION), a write access which has not been programmed into the function is indicated for this variable. This write access is located in the initialisation logic of the function. The initialisation logic is an implicit code, i. e. it is not indicated by DDS. However, DDS automatically generates this logic for every function.
Possible diagnostics?
With the help of the menu item Project>Global search, you can search for all locations in the program to which a variable was programmed. They are indicated in the DDS message window. The implicit code generated by DDS is ignored during the search process.
Short-term measures/recommendations?
The 'Global search' function can be used alternatively to the cross-reference list.
Evaluation:
The cross-reference list is very useful for trouble shooting, since not only the location of a variable in the DDS project is indicated, but also its type of usage (write, read). Displaying a non-programmed ('existent') write access confuses the user.
