J
I've been trying to send a command to a MODBUS/TCP device and read the response by reading and writing to a socket with Perl. Using Ethereal to sniff a closed source MODBUS/TCP client, I thought it would be very simple, but I have yet to get a response of any kind. I've opened socket to the device, port 502 tcp, sent it the 12 bytes I saw sent by the closed source client, and... nada in return. Something I'm missing?