Modbus TCP Server on port 502

#1

Hi .
I am trying to create a TCP modbus server on standard port 502, but when using this port , I do not know why but the system crash.
Does anyone have experience in this matter?

Thanks

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#2

How are you trying to create the modbus TCP server? If you are using a node-red node then tell us which one (node-red-contrib-something possibly).
Assuming the question does involve node red then seeing the node-red log might be very helpful. How to get that depends on your operating system. If the mechanism that you use for running node-red shows you message starting with Welcome to Node Red then that is what we want. If you are not seeing that then possibly running, in a terminal window the commands

node-red-stop
node-red-start

will show it. If not tell us the OS.
If you can see the log then first look to see if there are any messages that tell you what the problem is, otherwise copy/paste the log here down to the point that it crashes. If the log does not show any evidence of the crash explain exactly what you mean by crashing.

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#3

Not to bump an old thread, but for anyone who comes searching, the most likely culprit is needing root access to listen on a port less than 1024, assuming you're running Node-RED on a Linux device.

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