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Thread: SB9600 PTT Command

  1. #1
    Klyken No Longer Registered

    Default SB9600 PTT Command

    Does anyone know the proper command string on the SB9600 from the MCC5500 to PTT a consolette


  2. #2
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    Opcode is 2E, before the opcode there is a 01 for key and 00 for dekey.

  3. #3
    Klyken No Longer Registered

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    Thank you, are these codes listed somewhere, now that the patent for the SB9600 protocol has expired? I also need to have the MCC5500 console generate DTMF tones. The reason why I ask is I have created a low cost paging scheme for Volunteer Fire, basically I have developed a DTMF overdial function within the subscriber radios that responds in the same manner that two tone paging did in the conventional world, but these VFD's are now having to move to the Motorola 700/800 MHz trunking and need a solution. All I need is the ability to PTT the P25 trunked consolette and broadcast the DTMF Page call from the MCC5500, I am assuming I will need the command string for the DTMF as well.

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    DTMF is going to be a little bit trickier and I can't think of how to pull it off. If you know of an application that uses sb9600 to cause the radio to make DTMF on the air then I suggest you sniff its comms. I wrote a simple sniffer but it's far from complete and not very good... a wireshark module would be better.

    Keying the radio via SB9600 is a little more than just sending the 2e opcode, the radio will send a status back saying it's keyed and you should wait for this. (This will handle any kind of wait for grant or bclo situation)

    I found a bunch of opcode descriptions in some data files included in the mw520 package.

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    Quote Originally Posted by Klyken View Post
    now that the patent for the SB9600 protocol has expired?
    I am not a lawyer but I did not see anything in the patent that is not obvious to anyone who has ever used a multidrop bus before, even in the 80's when this stuff was thought up. If there is really anything innovative in there they lost out bigtime by not suing anyone who ever implemented two micros that communicate into bankruptcy. Just my thoughts about that from a technical perspective.