FCV NMEA 0138 Ports - Does it have 1 or 2?

[Anonymous]

G'day All,

I have a FCV585 and have had my old Garmin 128 connected to it for many years to provide Lat/Long to the sounder and it worked fantastic.
I recently upgraded my Garmin unit to a GPSMAP 820xs and thought that I may be able to get the units to talk so that I could mark a waypoint on the 585 and have it appear on the Garmin plotter.

That aside, I am confused as to the connections that make it all work. The Garmin has 2 x NMEA 0183 ports and when I check the 585 I can monitor 2 ports aswell. I orginially connected the units the following way -

Furuno Garmin
TD-A (White) - RX Port 1 (Brown)
RD-A (Yellow) - TX Port 1 (Blue)
TD-B (Blue) - RX Port 2 (Violet)
RD-B (Green) - TX Port 2 (Grey)

I couldn't get the Lat/Long to display on the 585.

So I changed things around to

Furuno Garmin
TD-A (White) - RX Port 1 (Brown)
RD-A (Yellow) - TX Port 1 (Blue)
TD-B (Blue) - NC
RD-B (Green) - GND

It now shows Lat / Long... albeit WRONG!!! It differs from what the 820xs states.

To me it seems that the 585 has 1 NMEA 0183 port with the pairs being White&Blue(shield) for TX and Yellow&Green(shield) for RX would this be correct? However I can monitor 2 NMEA ports on the 585 and see data transfering on both.

Bloody confusing to say the least.

Any suggestions on how best to hook these two units up and does the 585 have 2 individual 0183 ports or is it that even though the ports on the 585 and labeled 1 & 2 they are infact TX & RX of a single port.

Cheers all

Heath

 

[Snips]

Spaniardking,
Basically the FCV-585 has one input and one output port. However as you can see below it can be reprogrammed for two inputs for certain conditions. Note that Garmin's ports are RS-232 which use a common ground where the 585 has RS-422 ports which has isolated grounds. Since the ports have a difference in the grounds it is best to use a convertor to protect the ports. However if you want try having the 820X send info to the 585 you can connect the blue/black wires from the 820X to the yellow/green wires on the 585. If you want data to go from the 585 to the 820X use the white/blue wires of the 585 to the brown/black wires of the 820x.

Snips

 

[Johnny Electron]

I would also note that Garmin units don't tend to support the standard NMEA 0183 TLL NMEA sentence, so a mark/TLL from the Furuno will rarely ever work on a Garmin.