I'm trying to Modbus TCP to a BRX that is behind a StrideLinx VPN router, via a network local to the WAN port, not through the VPN. I can't get it to work.
I have port 502 forwarded in the router setup
I have 4 sessions, port 502, 60 second time out, enabled for Modbus/TCP Server Settings
I am testing it via modpoll, and instantly get response Network connection was closed by remote peer!
I tried same modpoll test on test BRX and a PC on the local LAN, and succeed.
I can "login" via telnet routeripaddress 502
I get no activity in ModbusTCPServer.ActiveSessions, .Errors, .Transactions
Any other things I can check or test?