Access Your Quantar Using a Cisco Router

The AUX port on Cisco routers is a asynchronous serial port configured as data terminal equipment (DTE). Adapters for connections to PC terminals, modems, or other external communications equipment are available, or can be DIYed. Sounds not to bad as a starting point to try if it is possible to get access to the serial port of the Quantar repeater. In most cases the AUX port is not used and no configuration is applied to the port, of course that needs to be changed, a few commands are added to the line aux 0:

no exec - only Incoming connections  
(modem InOut - allow incoming and outgoing connections on that line)
transport input all - allow all protocols on incoming calls
transport output all - allow all protocols on outgoing calls
stopbits 1

Now it’s time to build a cable between the router and repeater, nothing special RJ45 to D-SUB 9:


Next let us find out what is the right port number when the connection should go direct to the AUX port insed to the routers VTY line. It is 2000 plus the number that the AUX line has. We need to do a sh line and we will see something like this:


In this case the AUX port is line one which translates to port 2001, so if we want a connection to the AUX port we have to connect via telnet to the routers IP using port 2001. If we connect to a Quantar which is connected to the router, we should get the stations prompt: ]-O.  We can enter for example the commands dorap and then MTR TX_PA_P1, this gives us the status of the stations PA.



It is a working connection utilizing a Cisco router. The next steps are trying to map this to a COM port and use the CPS to read/write the station. If we use the command FPM  insted of MTR TX_PA_P1 the station spit out a more general report, this can be used to build a status monitor. If the connection is refused, there might be a active connection, or old configuration interfering, do a clear line 1 and see if it helps. There are way more telnet commands for the Quantar, but that is outside the scope of this write-up. More research and experimentation needs to be done, but it is an interesting starting point. If you have additional information or even accomplished to read/write a repeater this way, or made your own status panel, it would be nice if you could drop us a line

4 thoughts on “Access Your Quantar Using a Cisco Router

  1. Hi
    Thanks for the information.
    I just used it with Florian dashboard to monitor my P25 Quantar repeater F5ZIW.

    Is there other commands available besides FPM and MTR TX_PA_P1?

    73 REmi F6CNB

  2. Do any of these commands work with the AstroTac 3000? We’re building out a P25 Quantar network here in Indiana and I’d like to setup a dashboard that can monitor the V.24 ports on the ATac…..

    • Yes, you can make it work with the AstroTac but I have not dumped the commands. You should be able to get the same data that is shown in the RSS. If I have time to dump the commands I will post them here.

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