DSC for Garmin GPS and Standard Horizon VHF

[davisr]

I'm about to purchase the Garmin GPSmap 541s. This is the new NMEA 2000 version, which also is said to work with NMEA 0183 electronics. I'm also thinking of buying the new Standard Horizon Eclipse DSC+ GX1100S VHF radio. This is a NMEA 0183 device, which is suppose to communicate DSC information to a GPS.

The online owner's manuals for the Garmin GPS and for the Standard Horizon VHF mention the various NMEA sentences that their respective devices support. It appears that there would be a conflict between these two devices, for the NMEA 0183 sentences that are mentioned do not seem to correspond. I can provide some direction quotations from the manuals, but before wasting everyone's time, I'm just curious to know if anyone has had success using these two electronic devices for DSC purposes. I would think so, especially since these are new on the market.

Thanks for your help,
Roscoe

[tallyhorob]

call or email garmin and standard horizon, they might be able to help a lot more. could not hurt

[Captain Bill]

I have a standard horizon radio hooked to the NMEA 183 output of a ray marine chartplotter. The Radio recieves position information from the GPS, it does not send data back to the GPS so it is only hooked to the NMEA 183 out(chartplotter side) and there is no input connection from the radio to the GPS. What data do you want to send to a GPS from a radio?

The GPS puts a lot more data on the wire than the radio uses. It simply ignores the stuff it doesn't use.

[davisr]

It's my understanding from reading the blurbs about the new Standard Horizon DSC+ GX1100S that it outputs DSC information to the GPS. This enables you to see the location of another person's vessel (with which you have DSC contact) on the GPS chartplotter. The VHF dot matrix display itself shows the Lat/Lon of the other person's vessel, but when interfaced with the GPS, it also shows that vessel's position on the chart.

[davisr]

Here's what the two online owner's manuals say about these products:

Garmin 540 and 541, "Configuring Communications Settings": Serial Port 1, Serial Port 2: NMEA Standard: Supports the input or output of standard NMEA 0183 data, DSC, and sonar NMEA input support for the DPT, MTW, and VHW sentences," p. 44.

Standard Horizon DSC+ GX1100s: "NMEA Supported Sentences": Input: GLL, GGA, RMC, and GNS (RMC sentence recommended); Output: DSC and DSE."

If this makes sense to anyone, I would appreciate a helping hand.

Best,
Roscoe

[davisr]

For the sake of anyone else out there who might ask the same question, it appears that there are no compatability problems between the above mentioned electronics. They can indeed talk back and forth to each other. At the advice of Tallyhorob, I emailed tech support people both at Garmin and at Standard Horizon. I have not yet heard back from Garmin. Standard Horizon, however, quickly responded with the following message:

Roscoe

Thank you for contacting Standard Horizon.

GX1100S

541s

Wire color

Description

Wire color

Description

Green

Common

Black

Ground power and data

Purple

NMEA Out+(DSC)

Brown

NMEA In+

Blue

NMEA in+ (GPS)

Blue

NMEA Out+

Best regards,

Scott

[davisr]

As you see, the format of the table got rearranged when I pasted the tech support email in my posting. Attached is a Word document that preserves the format. Hope this will help someone else.

Best,
Roscoe

[osirissail]

From reading the manuals for the two different brand units - they both say that you must use "their" brand of radio and plotter to utilize the DSC ship position data information. So both radio and GPS/plotter need to be from the same manufacturer - at least that is what is in the manuals.
- - It seems that the incoming DSC distress or specific location request information can be transferred to the GPS/Chartplotter and displayed. Also AIS information can be transferred to the GPS/Chartplotter and displayed on the screen. Additionally, the Garmin unit has a statement that you can select a specific AIS target and then transfer the "calling" information to the VHF radio's DSC function directly instead of having to type in the MMSI manually. That seems like a good feature.
- - However, again, both manual mention that both radio and GPS/Plotter need to be from the same manufacturer.

[sck5]

I have a Garmin 4210 plotter and a SH eclipse VHF - I haven't tried to do ship position reporting but they talk to each other just fine - the radio shows the lat/long as reported from the gps (so long as it is turned on)

[osirissail]

For as long as DSC has been around (10years) GPS or GPS Plotters have been able to talk to a DSC radio and the radio can display your current lat/long and use it in the emergency DSC function. What is new is now the radio seems to be able to talk back to the Plotter/display/nav program and give it the locations (lat/long) and identifiers of DSC location requests and DSC emergency data and also AIS targets if the radio incorporates an AIS function. Something new under the sun . . .
- - The question is - does both the GPS/Plotter and the DSC/AIS VHF radio have to be from the same manufacturer or can different manufacturer's models of radios that also incorporate these new functions be connected together and "talk" to each other? This harkens back to the manufacturers trick of using proprietary data stream protocols (e.g. Sea Talk, Navnet, etc.) so that you could not mix and match components. You had to stay with one "brand" to be able to integrate the system.

[davisr]

In this case, when the manuals mention that you should use the companies' own products, it seems to be just a marketing scheme. You know, it's sort of like when you buy a certain brand of latex house paint the instructions say that you should first prime the surface with that company's own brand of primer (rather than use some big name primer such as KILZ from another manufacturer).

When you deal first hand with the tech people at Standard Horizon and Garmin you get the sense that they are accustomed to people asking them many times about this compatibility issue.

Today I received an email response from the Garmin tech people to the following question: "Will the GPSMap 541s fully communicate with DSC VHF and vice versa?" Here is what they said:

Dear Roscoe Davis,

Thank you for contacting Garmin International.

I am pleased to assist you. The GPSMAP 541s is fully compatible with
your Standard Horizon DSC radio. We assist customers connect that radio
to our chartplotters every day. Our chartplotters offer all NMEA
sentences necessary.

Please let us know if there is anything else we can do for you.

With Best Regards,

Michael H
Product Support Specialist
2nd Shift Marine Team
Garmin International
913-397-8200
800-800-1020
913-440-8280 (fax) Att: Michael H, Associate #6126
Garmin | Follow the leader

[Andrey]

Hi Roscoe,

Did you manage to display DSC data from VHF on your plotter? If so, which sentence did you use - DSC or DSE? Do you know the formats of the sentences?

(I am trying to do the same thing - pass coordinates received in DSC message to a chartplotter. Just started.)

Thank you,

Andrey

[davisr]

Hello Andrey,

I wish I had an answer for you. It was not until the spring that I purchased these pieces of equipment (during a big sale). I was then diverted by home improvement issues. Have just now returned to my rewiring project. Please let me know what you discover. Will pass along what I find when I reach that point in the project.

Thanks,
Roscoe

[richardhula]

NMEA 0183 is a common protocol for these devices. If the radio sends DSC/DSE data sequence then it will show up on the GPS display.

Equally the GPS device can send position data to the radio.

You simple need one screened cable between the two devices with three wires. Send to receive in both directions + common ground/signal -ve.

[richardhula]

Although not strictly related, a Brookhouse multiplexer as described here could answer almost all NMEA 0183 compatibility issues, allowing data from a non-compatible NMEA sentence to be custom translated into a similar but compatible sentence.

Since there is a high level of duplication of data when comparing that carried within each NMEA sentence, it should be easy to find a compatible sentence & convert accordingly.