COM port does not work on pfsense

  • Dear All,

    I am writing Java application to collect data on COM ports and it works great on Windows and Linux. It can collect data data via COM ports okay but it does not work on pfsense at all. It seems that the COM port is locked by pfsense as it locks port for pfsense console.

    Could anyone advise how to make COM port work on the pfsense? Or anyway to unlock COM port from the pfsense console (or this is truely locked by console for pfsense?)?



  • Full or embedded install?

    I suspect that editing /etc/ttys (and then rebooting) may help, but if you're on embedded you may just have shot yourself in the foot ;)  Alternatively, install another COM port and avoid the problem of what'll break when you upgrade pfSense next.

  • Thanks for your response. We install pfsense on the normal PC. How should we edit the file to enable COM?



  • The fact that you're asking that question suggests you're not terribly experienced with *nix.  I'd strongly advise that you test this on a virtual system first, rather than doing it on the real system - I don't know what will happen when you do this.

    Now, the fact that you installed on a normal PC doesn't mean you've got a full install.  If you have the packages menu then you've got a full install and the following may not break your system:

    1. Log on to the pfSense host either on the console or via SSH
    2. Select the option for a shell
    3. Type: vi /etc/ttys
    4. Comment out the lines beginning with ttyd[0-3]
    5. Save
    6. Reboot
    7. Cross fingers ;)

    I've never done this on a pfSense host and have no idea what the result will be.  It may free up the COM port, it may break your system.

  • When we edit the file, the whole system just crashed  ::). We tried to add a new COM port card into the PC and it can detect and our application can list the port. But all ports still seems blocked as it cannot receive anything when sending through newly added COM port.

    Could anyone advise how to make this work? Our application in Java surely works on Windows and Linux and it can list ports on the pfsense as well. There must be a blocking on the system.


  • I never had to edit /etc/ttys to use the com port with NUT (Network UPS Tools). I'm thinking this is an application problem. Might try on a full install of FreeBSD to see if it works. If it doesn't then modify your app. If it does see whats different between it and pfSense.

  • Dear All,

    As I check that cuad0 is not available with from Java Comm application port list when run on pfsense.
    How can I enable this COM Port(cuad0) to available on pfSense and the java comm application list it for activate comm port.

    Thank in advance and please with any idea.

    Best Regards,

  • Dear All,

    We are still struggling to make COM port work on pfsense. Could anyone give us a simple script or any suggestions to make us to be able to receive data from COM port?

    Any advice would be highly appreciated!



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