RLM stands for Repeater Link Mail server. It's PC-based, DOS program that operate as an repeater controller with link and voicemail or a stand alone system as simplex voicemail system. RLM is made for amateur radio usage.

  • RLM Homepage
  • Short history
  • Program description
  • License the program
  • Sequences
  • Link system
  • Login system and DTMF commands
  • Voice mail system
  • Time controlled events
  • Modem / terminal port
  • List of some major features of RLM
  • What can I NOT do with RLM?
  • What do I need for my system?
  • Some data and system requirements

  • Short history

    It started in 1993 when I wrote the first version in Qbasic only for our repeaters local use.
    Tourists who passed became very interested in our system with voicemail and link functions.
    As the program were specially written for our repeater and had no configuration possibilities, the program could not be used easily on another system.

    The year after I went to school and I got some time over for my HAM-hobby.
    I rewrote the whole program, this time in C++ and Assembler, and I also made it easy configurable.
    I did also construct an easy to build interface for controlling the radios and other peripherals.

     Example of some of the menu screens in the RLM software.

    Program description

    RLM is very flexible and fully configurable. With your fantasy you can make a very nice and peronalized repeater and voicemail system.
    RLM can operate as a… 

    License the program

    RLM is nowadays freeware. You can download the program and use it as much as you like.


    You configure the repeater in so called sequences. It is an event that happens in different times when the repeaters are operating. Some examples of sequences are:

    "Sq Rpt Open", "Sq Rpt Close", "Rpt Closing", "Link channel busy", "If not identifying before sending DTMF tones", "RPT hang-timer timeout"…
    There are also sequences for persons who activate the repeater but dosen't identify themselves and sequences for ID timers and Link system.
    For example, when the repeater is opening the "Start repeater" sequence is run and it could look like this…

    1. DELAY 500ms
    2. CW "SK2RME", SPEED 90, FREQ 700Hz
    3. DELAY 300mS
    4. FM SOUND no 1, tone 550

    Description of the sequence
    When the repeater is activated, (through SQ open, Accesstone or DTMF) the transmitter is starting and RLM wait for 500mS and then starting to key the text "SK2RME" with 90 characters per minute and with 700Hz tone frequency.
    There is a 300mS delay and at last does the FM-sound generator on the SoundBlaster card generate a "Bong" with tone frequency 550Hz.
    These FM sounds are fully programmable through a menu in RLM.


    Link system

    RLM handling a repeater but it can also handle a simplex linkradio. This linkradio can be used to link to other repeaters or only as a simplex link channel. The voicemail system can be also being operated from the linkradio. So if you link your repeater to another, the other repeater can use DTMF commands and the mailbox. You can also select channels on the linkradio from RLM. This could be done both with 8 bits parallel ports via the interface, or serial via a Com port on your RLM computer.

    The system supports scanning in background and a user of a repeater that your system is linked to can start up your repeater and use the mailbox.
    You can set per channel if the DTMF commands will be available from the linked repeater. You can also program a welcome message per channel when it's activated.


    Login system and DTMF commands

    RLM is based on that every user has a 3-digit login number. (E.g. 643 for SM2UMH)
    I have done this for some reasons.

    The users can (if the sysop wants) add themselves to the system and record their own callsign.

    The sysop/user can set parameters on per user basis that for e.g. control if RLM will repeat a question if you don't answer or how long time RLM waits for a action from you. This is good for different behavior with experienced and not experienced users.

    RLM has about 110 DTMF commands. The DTMF number is not changeable. I have done this so you can recognize the commands if you want to use another RLM when visiting another town. Although you can set access and lock commands as I described in section 2 above. You can also set a "prefix" on your RLM if two RLM systems are in conflict. For example: the command 3 for recording a personal message will be *3 if I set prefix * on my system.

    You can also create your own DTMF functions in a file called COMMAND.CFG.

    An example of a command could look like this.

    DTMF A1 ' Function "A1" for rebooting RLM
    PLAYHD Quest ' The file Quest is containing "Do you really want to reboot"
    ASK ' Answer 1 or 0
    CW Goodbye 100 1500 ' Keying Goodbye if answer is '1'
    WARMBOOT ' Shut down RLM and restart computer
    ELSE ' If answer '0'
    SPELL OK ' Play O.K.
    CW puhh 150 1000  

    There are many commands that you can use in your COMMAND.CFG. It is commands for setting ports, checking program flags, such as burglar alarm and if link or rpt is activated, playing an recording files, running external programs and functions for sending and receiving on comports.


    Voice mail system

    RLM has a powerful voice mail system. The users can record personal messages to other users or they can record a bulletin that is active between two dates.
    For example you can record a bulletin that that will pop up and announce for a club meeting and it will delete it selves the day after. RLM knows which user who has listen to which bulletins so the user won't have to hear it twice.

    There is also a function that is called "the loop". This is a stack with 10 messages and if you record a new msg. then the oldest one is deleted. It is just like a scrapbook on the RLM



    You can configure RLM to log in 5 files.


    RLM also creates a REPORT file every midnight. It is made up of a template (REPORT.CFG) and this file can be used as a bulletin in a packet radio system so you can check the status of RLM (HD space, Who has mail, Repeater statistics and so on).


    Sceduled controlled events

    You can set up events that will happen in different times. This can be used to start external DOS programs, sending beacons and other stuff.


    Modem / terminal port

    RLM has a port where you can connect a telephone modem or other equipment for serial communication. This port can be used to administer and monitor RLM activity.

    You must enter a password to get access to the console. Then you can use commands as…


    RPT CLOSE Closing repeater
    SYSTEM REBOOT Restarting computer
    DEBUG Toggle the debug mode on and off (Displaying all that happens)
    SU Enter the setup menu
    UL List user database
    RE Show the report file

     And more…


    List of some major features of RLM


    What can I NOT do with RLM? 

    RLM doesn't have any telephone patch functions but it have a flexible way to write own commands so maybe you can make them your selves.


    What do I need for my system?

    At first you need a PC computer. It runs fine on 486 computer and later. If you want to record and play sounds you need a SoundBlaster compatible soundcard. And naturally you need to install the software. You can get it from my download page.
    In simulator mode you can tested and evaluate RLM without the interface connected.

    Then you need the RLM interface. This is connected to the parallel port and it include 16 outports, 5 inports and a DTMF decoder.
    You  build it yourselves.
    Remember that even if you buy a ready made interface from me you must have some electronic experience to connect and adapt the interface to your radiosystem. Examples of things you must know is how to invert a signal using a transistor and techniques for making a good audioquality.


    Some data and system requirements