Fixed VHF DSC does not talk to Handheld DSC

RichardS

RichardS

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We're back home from our one month cruise and I've a selection of technical questions which have arisen during our 650 miles.

Any help you you can give me would be much appreciated.

The first problem concerns my Raymarine fixed DSC VHF (I can't remember the model name but it's only 6 years old) and my new handheld Standard Horizon DSC HX851E.

I've been testing the radios whilst onboard and the radios can speak to each other using all channels in non-DSC mode, and both could communicate with the marina VHF in Greece.

However, using DSC, I can call the HX851 afrom the Raymarine nd everything appears fine but I cannot DSC call the Raymarine from the HX851. I've checked and double-checked the MMSI numbers so that is not the problem. When I call the Raymarine, the SH screen says "Waiting for acknowledge" but the Raymarine refuses to acknowledge the call, and I've tried pressing everything! There is no sign at all that the Raymarine is picking up anything from the SH.

I've looked through all the settings and read the manual for both radios and I cannot see anything on the Raymarine which permits it to make DSC calls but disables any incoming DSC calls.

I need to do some more testing with a third DSC radio from a neighbouring boat or similar when I am back in Croatia but I just wondered whether this was a problem which someone else might have encountered.

Many thanks

Richard
 
RichardS said:
We're back home from our one month cruise and I've a selection of technical questions which have arisen during our 650 miles.

Any help you you can give me would be much appreciated.

The first problem concerns my Raymarine fixed DSC VHF (I can't remember the model name but it's only 6 years old) and my new handheld Standard Horizon DSC HX851E.

I've been testing the radios whilst onboard and the radios can speak to each other using all channels in non-DSC mode, and both could communicate with the marina VHF in Greece.

However, using DSC, I can call the HX851 afrom the Raymarine nd everything appears fine but I cannot DSC call the Raymarine from the HX851. I've checked and double-checked the MMSI numbers so that is not the problem. When I call the Raymarine, the SH screen says "Waiting for acknowledge" but the Raymarine refuses to acknowledge the call, and I've tried pressing everything! There is no sign at all that the Raymarine is picking up anything from the SH.

I've looked through all the settings and read the manual for both radios and I cannot see anything on the Raymarine which permits it to make DSC calls but disables any incoming DSC calls.

I need to do some more testing with a third DSC radio from a neighbouring boat or similar when I am back in Croatia but I just wondered whether this was a problem which someone else might have encountered.

Many thanks

Richard
Click to expand...


Have they got different MMSI # one from the other?
 
charles_reed said:
Have they got different MMSI # one from the other?
Click to expand...

Certainly should have - you're not supposed to put a DSC handheld on the parent Ship license, and the Ship Portable will come with its own MMSI. The fact that the OP can call the Standard Horizon from the Raymarine suggests that he has done this correctly.

My gut feeling is to blame the Raymarine radio. Raymarine do instruments and autopilots reasonably well, but most of the posts about their radios seem to be complaints.

Pete
 
charles_reed said:
Have they got different MMSI # one from the other?
Click to expand...

Many thanks Charles and Pete.

Yes - the fixed VHF has a Croatian MMSI starting 238 and I registered the handheld in the UK with a 235 MMSI.

A bit off-topic but as I have registered the boat on the UK SSR I tried to change the VHF licence to a UK one but the Ofcom site would not accept the Croatian number. I phoned them this morning but they say that the radio will have to be removed and sent back to Raymarine for re-programming!

I can't be bothered with that so, unless I end up having to send it for repair anyway, I will stick with one radio with a UK licence and one with a Croatian licence.

Having said all that, they should still talk to each other I am sure.

Richard
 
RichardS said:
I can't be bothered with that so, unless I end up having to send it for repair anyway, I will stick with one radio with a UK licence and one with a Croatian licence.
Click to expand...

I doubt that's legal (UK registered boat with Croatian radio license).

The odds are that nobody particularly cares about the legality of the licensing, but the Croatian MMSI might raise eyebrows if you're in the UK (it's not clear from your posts). Have you had a look at your record on MARS?

Might also be worth checking whether there's a way of resetting your radio without sending it away. Some radios do have that facility, either with a secret button combination or by opening it and shorting a jumper on the PCB. OFCOM won't know about such details for each radio, so they give the standard "send it back to the dealer" answer.

RichardS said:
Having said all that, they should still talk to each other I am sure.
Click to expand...

Indeed they should.

Pete
 
Last edited:
On a side note, a hand held DSC may not be legal outside UK waters...

Some other Raymarine VHFs can have MMSI reset by:

Turning Set Off
Hold down FUNC, 16/9 and DSC (NOT distress!) button while turning on. Hold until bleeps.

Are you placing an actual call or a test call?
 
knuterikt said:
Why?
Source?
Click to expand...

From OFCOM's site:

The Ship Portable Radio Licence is not valid beyond UK territorial sea and we do not issue an international call sign with that licence, so the hand held VHF DSC cannot be used anywhere in continental Europe.
Other countries may not authorise hand held VHF DSC (or may not do so in the same way that we do). So, they could regard a hand held VHF DSC as being illegal under their legislation, even if it is switched to ATIS working. This could result in enforcement action by the authorities overseas.

http://licensing.ofcom.org.uk/radiocommunication-licences/ships-radio/faq/vhf-faq/
 
knuterikt said:
Why?
Click to expand...

As I understand it, the international regulations never envisaged handheld DSC sets, and the ITU radio geeks have been tying themselves in knots over it because an MMSI is really meant to identify a vessel, not a radio (if you have MF/HF you still use the same MMSI as in your VHF). So in theory the DSC handheld ought to have the same MMSI as the parent vessel, but then what if you want to call one from the other? And then you want to carry the handheld between various different boats? It just doesn't fit their view of the world, and they haven't figured out what to do about it.

For a number of years after DSC handhelds appeared, OFCOM in the UK refused to license them, because there was no ITU guidance on it. Eventually they seem to have decided that no answer is coming soon and it's silly to keep waiting, and have unilaterally gone ahead with a scheme in which DSC handhelds get their own MMSIs and never mind the theory that MMSI == vessel. They're only allowed to do that for UK waters, though - ITU will have to make their minds up before it can apply internationally. OFCOM also warn that this is a transitional scheme, and it's possible that ITU will eventually come to a decision which requires UK handhelds to have their MMSIs changed.

Pete
 
prv said:
As I understand it, the international regulations never envisaged handheld DSC sets, and the ITU radio geeks have been tying themselves in knots over it because an MMSI is really meant to identify a vessel, not a radio (if you have MF/HF you still use the same MMSI as in your VHF). So in theory the DSC handheld ought to have the same MMSI as the parent vessel, but then what if you want to call one from the other? And then you want to carry the handheld between various different boats? It just doesn't fit their view of the world, and they haven't figured out what to do about it.

For a number of years after DSC handhelds appeared, OFCOM in the UK refused to license them, because there was no ITU guidance on it. Eventually they seem to have decided that no answer is coming soon and it's silly to keep waiting, and have unilaterally gone ahead with a scheme in which DSC handhelds get their own MMSIs and never mind the theory that MMSI == vessel. They're only allowed to do that for UK waters, though - ITU will have to make their minds up before it can apply internationally. OFCOM also warn that this is a transitional scheme, and it's possible that ITU will eventually come to a decision which requires UK handhelds to have their MMSIs changed.

Pete
Click to expand...
The Norwegian Maritime Radio sent a recommendation to ITU and it have been incorporated into the ITU guidance.

Have a look at "Assignment and use of identities in the maritime mobile service" https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.585-6-201201-I!!PDF-E.pdf
It covers

  • Assignment of identification to ship station
  • Assignment of identification to coast station
  • Assignment of identification to aircraft
  • Assignment of identification to automatic identification systems aids to navigation
  • Assignment of identification to craft associated with a parent ship
  • Assignment of identities for handheld VHF transceivers with digital selective calling and global navigation satellite system
  • Automatic identification system-search and rescue transponder
  • Man overboard
  • Emergency position indicating radio beacon-automatic identification system

The Norwegian Maritime Radio uses the recommendation for "Assignment of identities for handheld VHF transceivers with digital selective calling and global navigation satellite system"
In fact existing Norwegian MMSI for ships where issued with the last digit = 0
So a handheld will get the Ship MMSI with 8 inn front and the 0 removed

Translated from http://www.maritimradio.no/lisens/fritid/handholdt/
Example: If the ship MMSI is 257500010, a handheld VHF with DSC should be programmed with MMSI 825750001.
You don't need to pay extra license fee if you have a fixed VHF with a license
Click to expand...

There are no warnings that these VHF's might be illegal to use in other countries.

I'm wondering if the warning from OFCOM is groundless?
I would think that as long as the MMSI MID number (Country identification) and the prefixes conform with the ITU recommendation you are safe, the main purpose of the MMSI is to have unique ID after all.
 
Ofcom's warning is not groundless... But it doesn't mean the boat police will be carting you off..

BUT UK Handhelds are being allocated MMSIs 2359xxxxx rather than 8235xxxxx. I suspect that shown a ships licence for 235900001 the authorities will struggle to identify its intended for a HH set. Probably harder to spot that 823500001

I suspect at some stage the UK may need to move to 8 no's. If for no other reason than there are only 10,000 2359 numbers so would they then do 2349 or 2358 (not sure whats already allocated!)
The whole number allocation is pants. 00235 for a shore station. why not do 23500 - so always put the country code then a device code! Too late now!

The Norwegian model assumes there is a parent ship. I use my HH on at least 4 different boats that call have a MMSI. So while I could have 235123450 for my boat and 823512345 for my DSC HH that doesn't make it obvious that I'm not on 8235123450 which is a mile away but I've transfered to my ,ates boat 235123460. In my opinion there should be no link to a parent craft for a HH. Also if you aren't going to use the last digit, use it for the set type so number 235123458 on that model!!
 
Just an update in case anyone else has a similar problem.

Raymarine have been very helpful as follows:

"We think there may be an issue here with the old and new style DSC call messages. It is possible the Ray55 may not be recognizing the sentence used if the SH is using only the new one, or maybe the SH is not recognizing the older sentence used by the Ray55."

Raymarine have offered to upgrade the radio firmware as mine still has the original v1.13 firmware. The upgrade cannot be done by the user so it looks like I will have to send the unit to Raymarine in the UK.

I had no idea that the DSC standard had changed over the last 7 years. This could presumably affect many DSC radios out there. Finding out that boats with a recent radio cannot hear the DSC distress call from your older radio (assuming that distress calls are similarly affected?) could easily ruin your day!

Richard
 
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