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SOS - What the heck is COH?!?

jjamesjjames Posts: 2,908
in NetLinx Studio
Does anyone know what COH means in "RS-232 Land"? We have a product (AvTech AVC707) where the format is: <ACT($FF)><COH><ID><FUNCTION><$7F> - and i haven't a clue what COH means, and can't find it in the manual either. I looked up an ASCII table, and of course, it's not on there - any ideas?

Thanks in advance!

Comments

  • ericmedleyericmedley Posts: 4,177
    jjames wrote:
    Does anyone know what COH means in "RS-232 Land"? We have a product (AvTech AVC707) where the format is: <ACT($FF)><COH><ID><FUNCTION><$7F> - and i haven't a clue what COH means, and can't find it in the manual either. I looked up an ASCII table, and of course, it's not on there - any ideas?

    Thanks in advance!

    Boy, a Google search doesn't turn up much info, does it...

    However, it is my guess that they are meainging a hexidecimal $C0.
  • jjamesjjames Posts: 2,908
    Yup - tried the $C0 as well - still nothing.

    Says nothing about mixing HEX and ASCII, so I've tried:
    "$FF,'COH',$00,'M',$7F" and a variety of others, still nothing . . .
  • Spire_JeffSpire_Jeff Posts: 1,917
    Could it mean Carrier Off Hook (can you tell I've been discussing old school modems? :) )? The only other thing would be that they meant SOH (Start of Header) $01?

    I couldn't find Carrier Off Hook, and as I recall, that was an escape sequence to send the command to the modem. Speaking of which, anyone know where I can buy cheap external modems? Anyway, since that seems very unlikely, I would guess they are referring to the SOH.

    Jeff
  • jjamesjjames Posts: 2,908
    Yup - also tried the SOH ($01) yet - no luck.

    Try ebay. ;)
  • Spire_JeffSpire_Jeff Posts: 1,917
    It might be quickest to just write a little timeline that sends out the command with a constantly increasing value. Throw a slight delay in between each command and create a button to start the timeline and stop it. Then use diagnostics to emulate the button push and watch the device for the appropriate action to be performed. When you see a response, push the button again and check the value of the code you most recently sent.

    Also, are you sure you have the correct ID value?

    Jeff
  • jjamesjjames Posts: 2,908
    Yup - correct ID, baud, etc. - just no freakin' clue what COH means! I can't even get a phone number to AVTech that is in the U.S. Talk about aggravating!
  • jjamesjjames Posts: 2,908
    Well - quick update - it was INDEED $C0, and not COH. They failed to mention that the ID of the thing could not be zero.

    I'll tell ya, the stupidity of some manufacturers is beyond me.
  • TonyAngeloTonyAngelo Posts: 315
    At least they gave you a clue, I've seen 232 documentation that completely fails to mention parts of the code that are required.
  • jjamesjjames Posts: 2,908
    BTW everyone, this was an AVTech AVC707. In the AVC707 manual, the zero has a striking resemblence to the 'oh', leading me to believe that well . . . that it was an 'oh'. It wasn't until I found a manual for a new piece by the same company that used the same protocol, and this time the assumed 'oh' had a dash through it. So anyway . . . it was trial and error that the ID had to be set to something OTHER than zero.
  • REBUILD_EVENTREBUILD_EVENT Posts: 127
    D'Oh! :-)
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