[FADCA] RFDCD on Spirit 2 TNCs

[Chuck Hast]

On Mon, 6 Dec 2004 08:57:40 -0500, bud thompson <budt at cfl.rr.com> wrote:
> Pin 5 on the standard TAPR 5-pin TNC connector is the RF DCD - or external DCD for the purpose of inhibiting the TNC TX when an external DCD line is connected to pin 5.  I can't find any reference in the Sprint, Spirit, or Tiny-2 technical manuals if this line must go to ground or go high to inhibit TX.
> 
> In the Kantronics 1200b connector Pin 2 of the 9-pin connector is used as the external carrier detect.  When pin 2 is grounded, TX is inhibited.
> 
> Is the logic the same for  the Paccomm TNCs?
> 
> That would be 'logical.'

Yes, that would. They are TNC-2 clones I will have to see if I can run down the
TNC-2 spec, but the quick way is just to pull the line to ground and see if the
DCD LED goes on. Will do that when I get home this evening.

I think that the Spirit may have a jumper in there to invert the DCD
as there are
situations where that is needed. The newer Tinies may have it also.  Memory is
failing, I hope the rest does not follow suite.


-- 
Chuck Hast 
To paraphrase my flight instructor;
"the only dumb question is the one you DID NOT ask resulting in my going
out and having to identify your bits and pieces in the midst of torn
and twisted metal."