Topic: 998C to VHF Radio NMEA 0183

[fishesman]

I've been running a 998C HD SI for a year now and just picked up a 859CI HD. I plan to mount the units side by side on my console so that I can view more data at one time. I bought the Ethernet cable so that the units will share waypoint information and the AS Syslink cable so that both units can share the 998's external GPS antenna. The last piece of the puzzle is how to hook one of the units to my Simrad RS12 VHF radio. I know neither of these units has NMEA 2000 built in, so how do I connect one of them to the radio's NMEA 0183 connection? Is there another cable available for this?

[Humminbird_Greg]

fishesman,
Since you are using an external GPS Receiver you do not need another (Humminbird) cable.  The NMEA 0183 output connection is at the second shorter NMEA ‘pigtail’ connection cable that comes out of the GPS Receiver’s connector.  It should be about a foot in length and the end has a black plastic cap on it.  Remove the cap and there should be either a Red, White, Black wire set or a Green, White, Black wire set.  The White wire is the NMEA Output (+) and the Black wire is the NMEA Ground (-).  For some NMEA 0183 devices you will need to use the Green as the NMEA Output (+).  Be sure to set the NMEA Output menu to the “On” setting.

[fishesman]

Greg,

Thanks for the quick response. I don't remember the NMEA 0183 connector being there. Which end will find it? Near the antenna or near the plug that goes in the back of the 998?

Thanks

[Trout Bum]

Not sure about the 859 but with a 858 you would not need the AS Syslink cable to share the GPS. It can be shared over the Ethernet connection. I do this with a 998 and 958.

Relative to the radio GPS connection, it will depend on the baud rates of the radio and the GPS puck that you have. My radio would not mate with my HS puck but did mate with my non HS puck.

The pigtail wires from the GPS puck are located near the connector that plugs into the graph. Sometimes they are taped to the main transmission wire. They are about 6-8 inches long.

Go to the Bird website and download the GPS antenna manual and it will walk you through the process.

You may or may not need an adapter from the manufacturer for your radio. You'll need to check it's manual. I didn't need one for my Standard Horizon radio.

[fishesman]

I was aware that I could get by without the AS Syslink cable, but I wanted both units to be capable of running independently of one another in case one failed. I like redundancy in offshore equipment.

Thanks for the info on the GPS connection. My puck is non HS, so hopefully the mating process will be simple.

[fishesman]

I now have an 859 CI HD and 998C HD DI sitting side by side on my console. I'm trying to connect the 998 to my Simrad RS12 VHF radio via NMEA0183. I found the pigtail coming off the GPS puck, which is a GR50 with white, green, and black wires. The adapter cable coming off the Simrad has the following options: orange-nmea out(+), green - nmea in(-), yellow - nmea in(+), or black - nmea out (-). The Simrad uses a baud rate of 4800. I've turned on NMEA0183 in both the radio and on both Humminbirds (the HBs share the same GPS puck if that makes any difference). I tried every wire combination I could think of and I couldn't get the lat-long to display on the VHF. After changing wire combinations I switched the VHF off and then back on, but I didn't try rebooting the HBs. After looking at the wiring charts it appears to me that the correct combination should be black to black and HB green to VHF green or HB white to VHF green, but I also tried white to yellow and green to yellow. I twisted the wires together for testing purposes. Any suggestions on what else to try? Should I reboot the HBs after making a wiring change or should the lat-lon display almost as soon as the correct connection is made? Should NMEA 0183 be switched on or off in the 859 if the 998 is the primary unit or should it make any difference? Thanks for any suggestions.

[Trout Bum]

Nema Out must be turned on on the HB unit that is connected to the GPS Puck.

[fishesman]

Both of my HBs are connected to the same puck using the splitter cable. NMEA 0183 is turned on in both units.

[Trout Bum]

I don't know about the y cable for the puck.

My setup is a 998 and 958 with Ethernet.

I think you need the green and yellow wires (+/- Nema in) from the radio.

On the puck, I used the black (- ground) and green (+ NEMA out) wires.

If the above doesn't work, I would remove the Y cable and try it with just one graph.

[fishesman]

I had a few minutes before dark this evening to play with my NMEA 0183 connection again. I tried Trout's suggestion of using the Simrad green and yellow wires connected to the HB green and black. Still couldn't get the HB and Simrad talking! I thought for sure that was it. I didn't get a chance to try removing the "y" splitter cable from the puck. This is getting frustrating.

[Humminbird_Greg]

You are testing this where the GPS Receiver has a clear line of sight to the satellites, right?

Since you have both units set to NMEA Output “On” the SysLink cable should not make a difference unless there was something wrong with the SysLink cable itself.  So you may want to try it without the SysLink cable installed.

The correct connection does sound like the Simrad Yellow (NMEA In +) and Green (NMEA In -) which would mean either the Humminbird Green or White to the Simrad Yellow wire and the Humminbird Black to the Simrad Green wire.

[fishesman]

Yes Greg, I've always made certain that I had a GPS signal before testing the connection. I should have some more time to play with my setup this afternoon. Wish me luck!

[fishesman]

Thanks to both of you for your help. I finally solved my problem. I tried disconnecting the splitter from the GPS puck and hooking the radio to the 859 instead of the 998. Neither made things better. I finally decided to connect the wires in reverse of what I thought they should be and all of a sudden the lat-long was displayed on the VHF. My magical combination ended up being HB black to Simrad green and HB green to Simrad yellow. I'm not sure why this works, but it does! It seems backward to me, but I'll take it. Thanks again.