Converting serial port data to TCP/IP in a Linux environment

Question

You don't need to write a program to do this in Linux. Just pipe the serial port through netcat:

netcat www.example.com port </dev/ttyS0 >/dev/ttyS0

Just replace the address and port information. Also, you may be using a different serial port (i.e. change the /dev/ttyS0 part). You can use the stty or setserial commands to change the parameters of the serial port (baud rate, parity, stop bits, etc.).

I stumbled upon this question via a Google search for a very similar one (using the serial port on a server from a Linux client over TCP/IP), so, even though this is not an answer to exact original question, some of the code might be useful to the original poster, I think:

• Making a Linux box with a serial port listen on the TCP port to share the modem: ser2net
• Using this "shared" modem from another Linux workstation: remtty

You can create a serial-over-LAN (SOL) connection by using socat. It can be used to 'forward' a ttyS to another machine so it appears as a local one or you can access it via a TCP/IP port.

All the tools you would need are already available to you on most modern distributions of Linux.

As several have pointed out you can pipe the serial data through netcat. However you would need to relaunch a new instance each time there is a connection. In order to have this persist between connections you can create a xinetd service using the following configuration:

service testservice
{
    port        = 5900
    socket_type = stream
    protocol    = tcp
    wait        = yes
    user        = root
    server      = /usr/bin/netcat
    server_args = "-l 5900 < /dev/ttyS0"
}

Be sure to change the /dev/ttyS0 to match the serial device you are attempting to interface with.

Open a port in your server with netcat and start listening:

nc -lvp port number

And on the machine you are reading the serial port, send it with netcat as root:

nc <IP address> portnumber < /dev/ttyACM0

If you want to store the data on the server you can redirect the data to a text file.

First create a file where you are saving the data:

touch data.txt

And then start saving data

nc -lvp port number > data.txt