Windows Server 2019 and Modbus TCP communication problem

Question

Good morning , in an industrial application based on windows server 2019 we have to communicate with an instrument that have MODBUS TCP as a communication protocol .

the communication is set in the TCP port 502, I have disable the firewall

with free utility CAS MODBUS scanner i try a connection to the instrument at ip address

I try the same test with the same setting in a PC running windows 10 and the communication works correctly.

Is there a setting in windows server 2019 that has to be change to allow MODBUS TCP works,? I have already disable the firewall. Thank you

Answer 1

Found the problem or better the modbus gateway supplier did (Socomec).

Dave you're wrong, there is something different, it's called ECN (Explicit Congestion Notification) and it is enabled by default on servers, but not on the workstations.

netsh interface tcp show global (to check)

netsh interface tcp set global ecncapability=disabled (to disable)

source: https://support.softwaretoolbox.com/app/answers/detail/a_id/3320

Answer 2

No, there's nothing different here. I'd check with the industrial application vendor about support for server 2019.

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 3

Did you manage to solve the problem?

I have the same problem with windows server 2022. It works from windows 10 machine on the same network. Disabling firewall doesn't help.

I tested with a fresh install of 2022 server.