DSC compatability

[Great Lakes Lure Maker]

I just purchased a Uniden UM380 from Hills Valleys and Streams (very nice little unit). Once I installed it, I began to wire the units DSC with my Lowrance HDS. This proved to be a little more difficult than I would have expected. The NMEA wires were not "standard colors" and this made things a little confusing. It took some time to label the tx + and - for both units and the rx + and - . You would think the colors would be uniform, but they are not.  You need an MMSI # (merchant marine station id) which you can obtain for free from Boat Us.( I also purchased unlimited towing ins.)  Once you enter the MMSI # and you have all the wiring correct, you need to "enable" GPS output on the chart plotter menu. Then check the units set up. ( the GPS should support RMC, GLL, GNS, GGA sentences) After your positive the unit supports the correct sentences, then check the units Baud rate, Data Bits, Stop bits, data amplitude and Drive capability. (luckily mine was already correctly set)  Once you are done with all this, the unit should be reading your GPS position and should display GPS status ok. If you choose to, you can have your coordinates, speed, time and course displayed on the VHF screen.

 

Linking the GPS and VHF has several useful benefits however the most important feature would be the ability to hit the distress button (in the event you have an emergency) and have all that data transmitted to the coast guard automatically every 3 mins.  As well as any other vessel in range with DSC capability enabled. (your exact coordinates and nature of emergency will appear on their GPS) This leaves you free to attend to your situation while your radio is automatically transmitting your location, and other pertinent info, every 3 mins.

 

Mike, aka Iron Duke was helpful in finding the source of info on the internet needed to enable this feature, as it is not in either of the units manuals.  Many experienced installers have had difficulty with this process, which is why I posted it.

 

Hills Valley and Streams has excellent customer service!

 

Jason 

[lakebound88]

Even though its a nice feature, I was under the impression our axillary stations in new York which would see or should see the distress call do not have access to it. In the new york/great lakes region.

I may be wrong.

Nick

Sent from my XT907 using Lake Ontario United mobile app

[Tall Tails]

Nick is correct DSC is not available in the Great Lakes as of yet. 

[TyeeTanic]

I think it is available on the Canadian side of the lake.  I've definitely picked up DSC transmissions on my radio, so the other advantage is that any nearby boat will get the distress call with a location.

[Great Lakes Lure Maker]

According to some internet sites, DSC is available to all coastal waters as well as inland waters of the Great Lakes. I have emailed both the Buffalo and Sodus Coast Guard stations, just waiting for their reply. 

 

I agree with Markbelino, at least my transmission will reach someone if I send it. The way mine is set up, if someone within range sends out a distress thru DSC, I would get the distress, as well as their exact location positioned on my GPS. It seems to me if we have this available to our boats, wouldn't it make sense that any boat such as Coast Guard, Sheriff, or even the DEC would have this on their boats as well.

DSC transmissions are sent on channel 70, which is reserved for DSC only. Any station, on ship or shore with DSC capability enabled and within range would receive a distress sent DSC. 

 

I doubt as though I will get a response from the Coast Guard any time soon, but I will update when I hear from them. 

[Great Lakes Lure Maker]

I found this on the US Coast Guards Navigation Center web site. According to this, the system is world wide. A strong recommendation is issued to have all radios equipped with this tech to have it fully functional. You must also obtain a MMSI #, which identifies your boat to the Coast Guard, in case you need them. They are receiving distress calls from un registered radio's and it is causing problems. 90% of calls do not contain position info and 60% are not registered with MMSI #. 

 

The U.S. Coast Guard offers VHF and MF/HF radiotelephone service to mariners as part of the Global Maritime Distress and Safety System. This service, called digital selective calling (DSC), allows mariners to instantly send an automatically formatted distress alert to the Coast Guard or other rescue authority anywhere in the world.  Digital selective calling also allows mariners to initiate or receive distress, urgency, safety and routine radiotelephone calls to or from any similarly equipped vessel or shore station, without requiring either party to be near a radio loudspeaker.  DSC acts like the dial and bell of a telephone, allowing you to "direct dial" and "ring" other radios, or allow others to "ring" you, without having to listen to a speaker. New VHF and HF radiotelephones have DSC capability.

 

**The Coast Guard urges, in the strongest terms possible, that you take the time to interconnect your GPS and DSC-equipped radio.  Doing so may save your life in a distress situation! Before interconnecting your radio & GPS consult the owner's manuals.

 

As the Coast Guard’s new marine radio network, Rescue 21, becomes operational throughout the U.S., rescue centers will have the ability to receive instant distress alerts from commonly used DSC-capable VHF marine radios; however, approximately 90% of VHF DSC distress alerts received by the Coast Guard do not contain position information, and approximately 60% do not contain a registered identity. The Coast Guard cannot effectively respond to a DSC distress alert sent from such a radio. As a result, search and rescue efforts may normally be suspended when:

• no communications with the distressed vessel can be established;
• no further information or means of contacting the vessel can be obtained from other sources; and,
• no position information is known.

Last updated: 25 February 2014

Edited April 29, 2014 by Great Lakes Lure Maker

[Great Lakes Lure Maker]

Following is the reply I received from the Coast Guard station in Sodus. In short, Yes, DSC is working and must be installed and set up properly if it is needed. If you do not have an MMSI # your DSC will not work properly. Please read the following reply.

 

Jason

 

Sir,

Good morning, I am BMC Carey Jung from USCG STA Sodus Point. To answer your question, in theory your DSC will work if you have the DSC function interfaced with your GPS and a registered MMSI. With all that being said there is always conditions that could hinder this signal from being transferred to the CG i.e. poor GPS reception, improper installed equipment.

I would recommend having this setup by a prudent and reputable installer and have contingency plans to communicate if you are ever in distress. Cell phones, EPIRB (Emergency. Indicating. Radio . Beacon), flares and life jackets.

The following was cut and paste from a major boating store with a detailed explanation of how this system works.

DSC allows the radio to transfer information digitally, not just by voice, and to instantly send a digital distress alert to the Coast Guard. Part of that alert is a nine-digit Maritime Mobile Service Identity (MMSI) number that identifies your boat. The MMSI number is a bit like a phone number for your boat, and all DSC capable equipment (including AIS units) associated with the specific vessel should use the same MMSI number, since the MMSI serves to identify the vessel, not the equipment. If you sell your boat, the MMSI number is normally transferred with it.

Without an MMSI, the digital functions on a DSC-equipped VHF radio will not function. The MMSI number must be registered in a database that is relayed to the Coast Guard for use in Search and Rescue. DSC-equipped radios also need to be interfaced with a GPS when they are installed so that your position will be sent with the emergency message in a distress situation.

Please let me know if you need any further assistance.

BMC Carey Jung
USCG Station Sodus Point, NY
315-483-9816