Problem with IAC MMS configuration with Structured datatype
I am using SupervisionLib with 800xA 5.1 FP4 for my current project. As per documentation structure datatypes are allowed to used for IAC_MMS . If you refer to the attachments you can see the error I am getting while trying to configure IAC_MMS. vVariable1 is the communication variable I have declared, and vVariable2 is an internal variable which has to be used to write values to the communication variable.
The error as shown in the screenshot is : The variable/parameter is not allowed to be modified in this context.
What could be the possible reason and a solution for this issue?