The cable works because I used it to transfer the program to the CPU. 

In any case, many thanks

Hello Sultan;

Have you checked the messages logged to the CPUs' diagnostic buffer?

Whenever a diagnostic LED is activated, one or more messages are registered in the buffer, indicating what the CPU is complaining about, and giving hints for possible corrections to the configuration or programming of the PLC.

if you have trouble decyphering the contents pf the daignostic buffer use the Save As.. button on the diagnostic buffer screen to save the log which you can post here, on the forum, where we can have a look at it and try to offer suggestions.

Hope this helps,

Daniel Chartier