By RUGERO Tesla ( @404Saint ). S7comm is one of those protocols that looks simple until you start following the conversation all the way down. At first, there is just a TCP connection to port 102, then TPKT appears, then COTP, then Siemens-specific connection parameters, then the S7comm session has its own negotiation, then a memory address becomes meaningful, then a single function code can turn a packet from a read request into a write operation. That was exactly what I wanted to investig...