Please Note This forum exists for community support for the Mango product family and the Radix IoT Platform. Although Radix IoT employees participate in this forum from time to time, there is no guarantee of a response to anything posted here, nor can Radix IoT, LLC guarantee the accuracy of any information expressed or conveyed. Specific project questions from customers with active support contracts are asked to send requests to

Radix IoT Website Mango 3 Documentation Website Mango 4 Documentation Website

No ports shown on NMEA listener properties; want to read from file instead of port

  • The "NMEA listener properties" data source does not list any ports in its pull-down menu.

    I would like to fix that, but even if ports were listed, I need to read from a file instead of a local RS232 port. I set up a named pipe to redirect the serial port from a remote computer to the Mango computer by using mkfifo. I can 'cat' the local file to stdout and view the NMEA stream updating in real time, so I should be able to read that FIFO file rather than /dev/ttyS0. How can I do that? Reading from a file is also a useful way to import old NMEA data into Mango.

    But first, why don't I see any serial ports listed in the NMEA listener data source page?

    Linux 2.6.32-29-generic i686
    Distributor ID: Ubuntu
    Description: Ubuntu 10.04.2 LTS
    Release: 10.04
    Codename: lucid
    $ locate RXTXcomm.jar **
    $ locate **


  • Solution:

    In Debian/Ubuntu the serial ports are in group 'dialout.' However, user tomcat6 is not a member of group dialout, and consequently could not see the ports.

    $ ls -l /dev/ttyS*
    crw-rw---- 1 root dialout 4, 64 2011-03-23 20:42 /dev/ttyS0
    crw-rw---- 1 root dialout 4, 65 2011-03-03 10:28 /dev/ttyS1
    crw-rw---- 1 root dialout 4, 66 2011-03-03 10:28 /dev/ttyS2
    crw-rw---- 1 root dialout 4, 67 2011-03-03 10:28 /dev/ttyS3

    To fix the problem, user tomcat6 must be added to group dialout:
    root@ubuntuserver# usermod -G dialout tomcat6

    Now Tomcat6 can see the serial ports, but Mango will not report them until it is restarted.
    To restart Mango:
    root@ubuntuserver# /etc/init.d/tomcat6 restart

    • Stopping Tomcat servlet engine tomcat6 [ OK ]
    • Starting Tomcat servlet engine tomcat6

    Now Mango shows the serial ports in the pulldown menu

    When I searched for this in the forum, I had searched for 'NMEA.' Once I noticed the same 'missing ports' problem was also on the 'Modbus serial' data source page, I narrowed it to a serial port problem, and searched the forum for 'rxtx' and found out that [url=]'a reboot was mandatory,' so I restarted Tomcat.


    It would be useful to have a Mango wiki so that these issues can be organized and updated in a more structured manner than what a forum can support.