I’ve got a wiz55io module.It work fine with PING.
I write a Modbus TCP server program from Freemodbus.But it can't work.I capture the data to analyze this problem.I found the W5500 always send back RST in TCP handshake. Then I download a TCP_loopback program from website.It still work fine with PING,but still send back RST in TCP handshake. I don't know what wrong with it,please give me some advise! Thank you all.