[TenTec] HELP: OmniV computer interface cable question

[Dr. Gerald N. Johnson]

On Mon, 2008-02-18 at 12:40 -0500, OTAKEBI at aol.com wrote:
> Ed, I have a Belden 25 pin male to 9 pin female modem cable factory  wired.
> Do I have to do anything to it or do I just hook it up from OMNI V to  the 
> laptop?
> Will I hurt anything?
> Dan/N4VET
> 
> 
Won't hurt anything but won't communicate. RS-232 standards makes ins
and outs at both ends of the cable the same so the cable can be straight
when 9 to 9 or 25 to 25. That's when connecting the computer (Data
Terminal Equipment) to the modem (Data Communications Equipment). When
its said you need a null modem cable, you need to cross the wires from
in to make them connect to out at the other end. Grounds don't get
crossed. Most places that sell modem cables do have a null modem cable
or a null modem adapter.

I suspect you need pins 1 and 7 (on the 25 pin connector) connected,
plus 2 and 3 crossed. Those will be ground and signal. You may need 4
and 5 crossed for handshaking. And maybe 6 and 20 crossed. I don't have
the connections on the 9 pin end memorized.

73, Jerry, K0CQ