MMS Communication Error in PM861A controller.
Do you have more information? It is a bit short.
-On which Function Block or Control Module is the error? MMSConnect, MMSRead/Write.
-What is the error code, did you try to look it up in the help file?
-Did it work before?
-Is the communication between applications in the same controller or different controllers?
According to your screenshot:
Find out where this (global?) data structure is written. Somewhere in this program (local variable) or in another program in your application (global application variable, most likely) there must be an MMSRead block which writes to this bit.
Another approach: Go to the MMSCommLib and find the MMSConnect block. Right click and select Type Usage. This should show the program where the MMSConnect is located. You will probably also find the MMSRead blocks in the same program.