I'm trying to hook up a optoisolated DB9 cable/connector that I purchased
from Nautical Tech. (The Cap'n)..

I'm confused..

They are using two different gounds. One is suppose to be NMEA "B"(signal
ground) to GPS signal ground.
The other is called Capn Transmit signal ground to AP input ground (and/or
GPS/Radar ground)

The NMEA B is going through the opto-isolator so I can't tell what DB9 pin
it uses.. The Transmit signal ground bypasses the opto-isolator circuit and
is pin 5 of the DB9.

Here is the complete cable designation info:
Yellow wire-- NMEA "A" (recieve Data)-- connect to GPS output wire
Green wire-- NMEA "B" (signal Ground)-- connect to GPS signal ground wire
Red wire-- Capn Transmit Data-- connect to Autopilot input wire (and/or
GPS/Radar input)
BlackBrown-- Capn Transmit Signal Ground-- connect to AP input ground
(and/or GPS/Radar ground)

So far I have ignored the Capn Transmit Signal wire and it isn't hooked to
anything. My GPS is recognized and working fine with the software.. However,
eventually I want the navigation software will need to send XTE to the
autopilot..

I always assumed that XTE would be sent via the NMEA sentence.

I can't figure out what to do with the extra ground wire.

I can't get tech support from Nautical Tech. since I haven't been upgrading
my softwere since ver 6.3. etc..

Comments.

Steve
s/v Good Intentions