S Horizon GX2100 - Tech Assistance

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JohnMilsom

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Hi,

I have just bought and installed a GX2100 dsc vhf/ais receiver. I have installed it and it appears to be working well, including the ais facility now that I have connected my gps plotter to the unit. Very impressive unit.

However I have been struggling to connect up the gx2100 with my laptop. I am using a USB to NMEA serial adaptor cable. I seem to have to choose between either:

(a) connecting the input wire of the USB cable to the GPS data from my chart plotter at 4800 baud, or
(b) connecting the input wire to the brown AIS data wire from the GX2100 at 34800 baud

I can't seem to get both gps data and ais data from the brown gx2100 cable (which I think the manual suggests I should be able to). Do I need to get another (separate) USB to NMEA cable and connect the plotter to my pc separately? (This seems an obvious solution but will it work?)

I have tried using a variety of software on my laptop with the same results (Nepture Planner Plus, SeaClear2 and ShipPlotter).

I realise this is quite a specific request for help, but if any assistance from technical whizzos would be most appreciated!

John.
 
Not really possible....

Hi John,

I have a GX2000 which shares most of the features with your GX2100. The manual is the same....(YMMV)

Looking over the manual it states that only AIS data is available on the AIS NMEA line (brown wire). ANd that only DSC data (das,dse) is available onthe nmea out of the radio (gray wire).

The green wire is for gps input to the vhf. And, that no combining of gps and ais data is available. You may want to call or email SH support. I have found them to be very helpful. The feature may be available but the menu to turn it on not in the manual.

The radio assumes that you have a SH plotter which sources the GPS data and thus does not need it.

Assuming that there is not an option to output GPS on the AIS wire I have 2 solutions for you.

1) use 2 ports on your computer - one at 4800 baud for the gps data and one at 38400 baud for the ais data.

2) buy a nmea mux such as brookhouse makes and bring the gps data to both the radio and mux ch1, the asi data from the radio to the mux ais port (port 4) and then the mux output at 38400 to you PC serial port. The mux will combine the GPS and AIS data plus allow 2 more 4800 baud nmea inputs (DSC data and ??) to go to your PC.

Regards, Ethan
 
Thanks for the advice.

I have emailed SH Ethan, and will investigate your options (option a sounds easier though!).

I will try xport as well, thanks FullCircle.

I am very grateful for you guys taking the time to provide your advice.

John.
 
It appears that you are not getting the GPS position from the VHF feed, which makes sense because the VHF is a GPS position consumer, not a provider.

In your case you should get the GPS feed directly from the GPS receiver with a second serial/USB cable.

Alternatively, if you would like to keep your PC connectivity simple, install an NMEA multiplexer that can also convert the bps (bits per second) input rate from different devices (it is not baudrate that defines the frequency of modulation in general over a voice line).
 
I love reviving old threads!!

Anyway this afternoon (whilst skiving off work) I have installed my GX2100 and all seems well. However it has lead to more thoughts and queries!!

a) I installed an Evermore GPS SA320 for the VHF GPS. Searched the internet for the wiring, and it sprang in to life with just the GREEN wire from the gps connected to the BLUE wire on the VHF (contrary to what is stated above but as per the manual for the VHF). So what is the NMEA common for?? I don't get it!!

b) Then I want to use the DSC output and the AIS output from the VHF for my laptop running opencpn. I gather that the baud rate is different for these 2 outputs so am planning to use 2 dsub connectors - convert to usb, then use a usb hub and finally opencpn will sort it out apparently. But how to wire the dsubs?? Do they both need the common??

c) This is insoluable! Cant get behind the vhf to install the flush fitting ears! Going to have to drill holes I think in the sides of the switch panel space so I can screw them in! Is there any product I could use just to seal the radio in to the hole?? Or something??

d) Just to complicate matters I have a stowe NMEA databox which if I put GPS input into it will then send all the instrument data and the gps to the PC and my phone over Bluetooth for iregatta use! So I believe I can just us the output from the Evermore GPS, but the stowe has + and - so I assume I need the GREEN gps wire, and one of the others!!??!!

This is all confusing! But fun!!
 
Same gps?

SA-320-Wires.jpg



assuming so then the gps green should go to the gx blue, gps white to gx green. it might work without the white/green connection with both devices using the power negative as the second wire.

Not 100% sure but for OpenCPN you might need 3 serial/usb converers, I for gps, 1 for DSC and 1 for ais. Pretty sure you can't just join nmea wire together, they get confused all talking at the same time. the dsubs will share the radio nmea ground though.

I didn't even know DSC could get output over nmea, I use Opencpn as well and a gx100 so must investigate.

hope that helps a little.
 
GHA said:
I didn't even know DSC could get output over nmea, I use Opencpn as well and a gx100 so must investigate.
Click to expand...
DSC sentence on NMEA is usually a MMSI and position for another vessel. Either from a pos request or a DSC Alert.
 
roblpm said:
So what is the NMEA common for?? I don't get it!!
Click to expand...
Common, GND and -VE are all the same thing. So I'm guessing it works because there is probably another common GND somewhere - could even be the -ve battery connections provide the route through. But I WOULD connect the GND/Common connections as its the robust way to do it..
 
roblpm said:
Yes i think it pops up on opencpn, so if there is a mayday it gives you the boats position and info onscreen.
Click to expand...

Yip - actually a very useful feature. With a 70nm radius for DSC alerts thats a massive area that you might catch an alert from. At a glance being able to see how close someone is to you will make a huge difference if you are likely to be diverting to assist.
 
GHA said:
Same gps?

SA-320-Wires.jpg



assuming so then the gps green should go to the gx blue, gps white to gx green. it might work without the white/green connection with both devices using the power negative as the second wire.

Not 100% sure but for OpenCPN you might need 3 serial/usb converers, I for gps, 1 for DSC and 1 for ais. Pretty sure you can't just join nmea wire together, they get confused all talking at the same time. the dsubs will share the radio nmea ground though.

I didn't even know DSC could get output over nmea, I use Opencpn as well and a gx100 so must investigate.

hope that helps a little.
Click to expand...

Thanks for that, though the picture is still confusing, says 2 blacks!

So each dsub gets 2 wires, the relevant signal one and a split green from the radio. Any idea which pins?? I am sure you are right about the 3 dsubs, I think a usb hub will work ok and I read that the latest verision of opencpn has a virtual multiplexor which will sort everything out!
 
ShinyShoe said:
DSC sentence on NMEA is usually a MMSI and position for another vessel. Either from a pos request or a DSC Alert.
Click to expand...
Ah, now that's handy to know. So I can send a pos request to The good ship shiney shoe and when a position report reply comes in it will show up on Opencpn? Cool.
The gx2100 can actually automatically send pos report requests to up to 4 stations automatically every 1 to 40 minutes, so you could keep an eye on 4 mates if you had that many :cool:
 
roblpm said:
Thanks for that, though the picture is still confusing, says 2 blacks!
Click to expand...

No, it's saying that the black is both the negative side of the power supply and, optionally, the negative side of the NMEA. Apparently the VHF works the same way although it's not documented. This is why your kit managed to communicate despite you forgetting that a circuit requires two wires.

Pete
 
prv said:
No, it's saying that the black is both the negative side of the power supply and, optionally, the negative side of the NMEA. Apparently the VHF works the same way although it's not documented. This is why your kit managed to communicate despite you forgetting that a circuit requires two wires.

Pete
Click to expand...

The picture shows TWO blacks. The text shows TWO blacks.

I'd say the top black in the picture with the wire partially stripped further down is the VCC Ground. Chances are they both short internally anyway.
 
Last edited:
Well I am still confused as my GPS has 5 wires. I am not at the boat at the moment so cant remember the colours of the 2 remaining ones I haven't used but I am sure there is only 1 black one!

So from memory I have:
Red: +12v
Black: Power Ground (signal ground?!)
Green: +ve NMEA

2 others, not black, any ideas?

I have now seen 3 different wiring diagrams for the SA320!

Good product, terrible documentation!
 
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