I am new to the decetralized systems and I am trying to connect to IM151-8CPU with a PC through a standard ethernet card, but it doesn't seem to work.
I tried both standard ethernet cable and crossed, but still no result.
My ethernet card shows that I am not connected to any network and the Simatic Manager cannot find any device on the network using TCP/IP (AUTO).

Thank you UMENCHO for your instant reply.
It seems that the MMC, had an oldprogram and was triggering the CPU SF red light.
Once the MMC was removed everything was ok.