Serial Port Multiplexing (2 apps to 1 port)

Discussion in 'Linux Networking' started by Onslo, Oct 6, 2004.

  1. Onslo

    Onslo Guest

    Hello group :)

    For some time now I have been trying to find some way of implementing
    a method that will allow 2 (or more) serial communication applications
    to read and write to 1 physical serial port, and I have failed at
    every attempt. Hopefully someone can help me in my quest for a

    A solution to do exactly this under Windows is available :

    ** quote **
    5. Use TCP-Com to feed data from one physical RS232 port to multiple
    RS232 serial communications programs.
    Normally Windows will not allow two serial communications programs to
    open the same serial port at the same time however it is possible to
    use TCP-Com to feed data from a physical RS232 serial port to multiple
    "Virtual" serial ports so that more than one application program can
    input data from a single RS232 serial port.
    To accomplish the above, configure one instance of TCP-Com to open a
    physical serial port (COM1) on your PC and acting as a TCP/IP server
    using any port number that you like. Next, open a second instance of
    TCP-Com (select New from the TCP-Com File menu) and configure it to
    create a virtual COM port (COM2) and have it connect as a TCP/IP
    client to the TCP/IP port that the first (server) instance has been
    configured to use. Finally, open a third instance of TCP-Com and
    configure it to create another virtual COM port (COM3) and have it
    also connect as a TCP/IP client to the TCP/IP port that the first
    (server) instance has been configured to use. After you activate all
    three instances of TCP-Com, your computer will behave as if it had two
    additional COM ports COM2 and COM3. At this point, you can run two
    serial communications programs – one on COM2 and the second on COM3
    and both will be able to send and receive data in or out COM1. The
    arrangement described above will work for as many virtual COM ports
    that you wish to create so you can connect up to 98 separate serial
    communications programs to the same physical serial port.
    ** end quote **

    I would like to be able to do the exact same thing using Debian Linux.

    I have tried using a combination of ser2net
    ( and netcat (nc
    ser2net_ttyS0_port <> /dev/ptyp0) and minicom to talk to the slave end
    of the pseudo terminal pair. However, it would appear that ser2net
    does not support concurrent connections to the same serial port, as is
    the norm with serial I/O architecture.

    Does anyone know of a method of allowing the same function on Linux as
    quoted by the TCP-Com application for Windows?

    Kind regards
    Onslo, Oct 6, 2004
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.