Adding a NMEA 2000 Chart Plotter to a NMEA 0183 Network

[teppokurki]

Originally Posted by Dockhead

All modern plotters I've seen have 0183 inputs. AND, they will convert N2K sentences to 0183 inside the plotter.

Then you have not seen everything: https://www.bandg.com/bg/series/vulcan/ has only N2K.

[Dockhead]

Originally Posted by teppokurki

Then you have not seen everything: https://www.bandg.com/bg/series/vulcan/ has only N2K.

Thanks for the correction!

Instead of all , then, I say most.

[tanglewood]

Lots of questions before there can really be any answers.


1) You say "the 0183 connection to the existing plotter". Is there really only one? If so, there must be a multiplexer somewhere merging all the 0183 data together from the various devices. Or are their multiple input ports on the plotter, for each of the devices? It's quite common for older devices to have multiple 0183 ports for just this reason.


2) As mentioned, does the existing plotter also have an N2K port? If so, the plotter might be able to relay the data is already receives over to N2K. But the devil will be in the details. Not all plotters do this conversion, and those that do often only convert select data. You will have to plow through the plotter manual to see what it actually does, and what value this approach might bring. Maybe it can translate some of the data, and you can use a converter for the rest.


3) You should really consider the talker and listener of each 0183 port as completely separate beasts. In lots of cases the talker and listener will be connected to completely different devices. So you really need to understand how each is connected, and what it's being used for. So there is really no such thing as "connecting to an 0183 port". You always need to be specific about how the talker is connected, and how the listener is connected.



4) Further to #3, any converter that you would connect to the plotter would only be connected to the plotter's listener (with the converter's listener) so it is picking up the same data that the plotter is receiving and sending it to N2K. You would NOT connect to the plotter's talker or you would have two talkers which will not work.


5) On converters, they vary widely. At a minimum, most (perhaps all) can't handle both AIS and other data, requiring separate converters for each. You also need to watch the speed of each channel. AIS is always 38kb. Other 0183 data is usually 4.8kb, but can be 38kb is all devices are capable.


6) As mentioned, you need to be very mindful of what data gets translated in what direction, and should avoid creating superfluous data which will only be a possible source of confusion now and down the road.


I'd suggest your time would be very well spent to diagram out how you existing system works, accounting for every talker and listener, and noting the speed for each channel. Then you can start researching ways to get the existing data to a new secondary plotter. It can definitely be done, but you can waste a huge amount of time and money in trial and error. And I think you can get much more concrete advice from people here with more specifics. All the advice is good so far, but only in some specific situation which you may or may not have.

[SailingPNW]

Well on close inspection of the current chart plotter (an older Furuno) after pulling it out, there are 4 connections going to it, and going through the menu, I don't see a way to out put signal to another network, but will have to research that further. There is a 2000 Port though.

I think replacing everything might be the way to go, and while that's not really a short term option, it's also not necessary to network everything either.

[ibeeby]

This topic is interesting me as I recently (last year) plumbed in an NMEA-0183 based Chart Plotter on the upper helm of our flybridge (it had previously been rather informally wired in) and added AIS having secured an AIS transponder on eBay at a very reasonable price.


The AIS transponder does NMEA-0183 and NMEA-2000. The radio only does NMEA-0183. I've added a Seatalk to NMEA-0183 gateway to allow the chart plotter to receive depth and speed log information but I don't think that this is of much use (more fun making it work...).



Now we are looking to install a radar. Our chart plotter doesn't do radar (unless we want an American radar, which we don't) but we don't see the need for radar when helming from the flybridge anyway (so far). AIS gives us what we need when dealing with bigger vessels and we can see the smaller ones. The need for radar is to give us additional input in poor visibility in busier channels in and adjacent to shipping channels.



So the plan is to install the radar (4G) and connect it to a bigger plotter (12") in the lower helm. AIS can come down to both plotters over a native interface to each. We'll also be looking to put in a forward looking sonar but again only for the lower helm as it will be more use when running in shallow water or at low light. The AIS (NAIS-400) doesn't multiplex NMEA-0183 onto NMEA-2000 so the question is the radio connection.


We've seen the B&G plotters, one of which is NMEA-2000 only and the other has AN NMEA-0183 input as well. The dual-input model appears to be older. Will this soon be discontinued?


Long term plan will be to get a similar (but smaller) plotter for the upper helm when our old plotter gives up. So we'd want to be able to buy one with a slave capability and that is likely to remain available for a few years.


For mapping, we are currently very happy with C-Map charts. I'm working on building a bluetooth interface so that I can push routes to the plotter from the PC (using qtVlm etc) without having to run cables etc.



The question is, is it better to get a plotter for the lower helm with both NMEA-2000 and NMEA-0183 inputs or to use an NMEA-0183 to NMEA-2000 convertor for the radio connection? Also, should that be a bi-directional link? Our radio (Standard Horizon GX-1800) might have the facility to call a DSC station based on the AIS fix although our current chart plotter doesn't support that. We do get emergency reports from the radio on the plotter - this was demonstrated graphically (!) as we were arriving into Grimsby last summer when an emergency button was activated (by accident) on a nearby commercial vessel. Again, for the time being, we'd be content with sonar and radar facilities being only available on the lower helm.


Any thoughts welcome. If I need to draw a diagram let me know.


Ian

[svmobert]

Originally Posted by ibeeby

....Our radio (Standard Horizon GX-1800) might have the facility to call a DSC station based on the AIS fix although our current chart plotter doesn't support that. We do get emergency reports from the radio on the plotter - this was demonstrated graphically (!) as we were arriving into Grimsby last summer when an emergency button was activated (by accident) on a nearby commercial vessel.....

Ian

Standard Horizon does not implement the DSC call functionality on NMEA inputs (Icom does though). So you won't be able to initiate an outgoing DSC call from AIS or Chartplotter data using that radio. The radio does output received DSC data on NMEA0183 and that can be displayed on a chartplotter.

As far as N2K and NMEA0183, my recommendation would be to use an NMEA0183<->NMEA2000 converter somewhere in the system rather than worry about the chartplotter supporting both. Build out a new NMEA2000 network if you don't have one, then mux the older NMEA0183 devices into that network. Over time you will upgrade with newer devices and the NMEA0183 will go away. But having it independent of the plotter also means you can still use all those devices together if the plotter is powered off.

Also, some NMEA MUX combinations also have WiFi or ethernet connectivity so you can use a tablet or PC based navigation tool and bring AIS, GPS, depth, etc data into that, independent of the plotter.

The recent B&G plotters also have WiFi and will do the same as long as they are powered on.

[ibeeby]

Thanks for the valuable input Richard.


On reflection, the only NMEA-0183 device that is important is the radio. If it is only a talker then its straightforward to get an NMEA-0183 to NMEA-2000 convertor to drive the 'new' bus. The AIS outputs on NMEA-0183 and NMEA-2000 simultaneously so not a problem.


Does it then follow that the e.g. B&G display with NMEA-2000 only is likely to be a more recent model and therefore available for longer (should we wish later to put a slave on the upper helm) than the dual-bus unit?


We don't see the need to often switch between upper and lower helm when on a trip. Even if we could do this seamlessly with the electronics (ie with a slave MFD), the switching over of the engine controls requires us to be stopped and we have not found it to be easy (although this is probably just user experience).


Ian

[billknny]

There is nothing wrong with using a 0183->N2K converter. It will certainly work. Just be aware that most (all?) of the Navico (Simrad/B&G) MFDs have a 0183 input (and output!). I assume other brands do as well.

They take that 0183 input data and translate/convert it out to the NMEA2000 network. If you already have a 0183 MUX, you might as well let the MFD function as your NMEA 2000 converter rather than buy a rather pricey new device to do the same thing.

As you slowly weed out the older systems, you can just unplug them from the 0183 MUX and into the NMEA2000 net. That's pretty much the strategy we used for our system. By this point we have only N2K instruments, and the 0183 is only used to send data to the nav computer and VHF radio.

Choosing between various manufacturer's MFDs seems to be kind of like choosing an anchor. You pick the one you like best, and then defend it to the death. After a very short period of time the software interface of you bought seems intuitive and natural, and all the others seem to have the worst, klunkiest, user interface ever invented.

[continuouswave]

Unlike several others who have replied, I don't have great confidence in two notions introduced into this discussion.

One item that strikes me as overly broad and optimistic: any NMEA-0183 to NMEA-2000 convertor will convert all data between the two protocols. This is actually not possible, as there are data in one protocol that do not exist in the other. Even when the same data is available in either protocol, the notion that all convertors handle all this data is not well founded. For example, a well-know protocol convertor was unable to convert DSC and DSE sentences in NMEA-0183 to NMEA-2000. In as much as the radio is mentioned as being the primary device to use with the protocol convertor, the lack of DSC and DSE sentences would be a complete failure for a radio. Also, data related to NMEA-0183 AIVDM is often not translated, which is another important function if you plan to use a radio and a NMEA-0183 convertor.

Any NMEA-0183 to NMEA-2000 convertor being considered should be carefully checked to see which NMEA-0183 sentences it can translate to NMEA-2000, and with particular attention in the case of use with a radio, to verify the convertor can handle NMEA-0183 sentences DSC, DSE, and AIVDM.

The second notion that seems misleading is that any multi-function display devices with two ports, one NMEA-0183 and another NMEA-2000 can automatically convert data from one protocol to the other. I have never heard this ability mentioned by any manufacturer. I doubt it exists. If it did, why would there be a market for external protocol convertors?

Perhaps what was meant was any multi-function display device can show data on its chart plotter screen from either NMEA-0183 or NMEA-2000. Unfortunately this is not true, either. Some rather well-know brands of chart plotter are not capable of displaying certain AIS targets, for example, Garmin chart plotters do not (or at least did not for some time) display AIS Aid to Navigation targets.

There are no international standards or federal regulations that govern recreational boat chart plotters, so exactly what sort of outcome occurs when you connect them to NMEA-0183 or NMEA-2000 data is not exactly guaranteed.

[ibeeby]

Thanks for the further input. I've been silent on the specific displays so far but to be clear, I am looking at the Simrad NSS12 or GO12 XSE displays. Each has NMEA-2000 and the NSS12 has a NMEA-0182 port.


If we are to later adopt a slave to the main display (ie our existing older plotter gives up or shows its age) then we'd want to be able to buy one of the similar model (such as NSS9 or GO9 XSE) for compatibility.


Otherwise, noting the helpful comments regarding NMEA-0183 to NMEA-2000 convertors and radios, I am not too bothered about having a convertor or relying on a single NMEA-0183 input to the MFD.


The only NMEA-0183 device which is essential is the DSC radio. The AIS is an NAIS-400 which has simultaneous outputs on NMEA-0183 and NMEA-2000 ports. Therefore the two chart plotters can use different data inputs for that if needed.


Does anyone have any idea which of the NSS or GO* MFDs are the older model (and therefore more likely to be discontinued first)?


Ian

[svmobert]

Originally Posted by Dockhead

Thanks for the correction!

Instead of all , then, I say most.

Actually.. It's probably about half now...

Raymarine Axiom only has N2K. If you want 0183 you have to spring for the Axiom Pro (as an example)...

Most manufacturers are eliminating 0183 in the lower end to keep costs down.

[thlamers]

All should be advised that NMEA is just now finalizing the next generation of marine electronics interfaces. It will be an Ethernet linked system using Internet protocol for the data format. In addition to putting high rate data content such as maps and radar on the boat's net it will also facilitate connecting the boat net to the internet for various purposes such as remote tracking and monitoring.



Raymarine has offered Ethernet networking for several years so the idea is in use but I do not know if the Ray system will link to the new NMEA one.

[PirateGuy]

Originally Posted by thlamers

All should be advised that NMEA is just now finalizing the next generation of marine electronics interfaces. It will be an Ethernet linked system using Internet protocol for the data format. In addition to putting high rate data content such as maps and radar on the boat's net it will also facilitate connecting the boat net to the internet for various purposes such as remote tracking and monitoring.



Raymarine has offered Ethernet networking for several years so the idea is in use but I do not know if the Ray system will link to the new NMEA one.

Hurray!

Now we won’t just have one obsolete communications standard, we will have 2.

I’m in the middle of trying to patch a Nmea2000 device to Raymarine STng (thank you RM for having the courtesy to your users to come up with non-standard connectors to try to drive business to yourself) with some difficulty.

Bill Gates made a fortune by continually “upgrading” operating systems. I guess marine electronic manufacturers want the same opportunities to gouge their customers.

[continuouswave]

Originally Posted by thlamers

All should be advised that NMEA is just now finalizing the next generation of marine electronics interfaces. It will be an Ethernet linked system using Internet protocol for the data format. In addition to putting high rate data content such as maps and radar on the boat's net it will also facilitate connecting the boat net to the internet for various purposes such as remote tracking and monitoring.

If NMEA continues its practice of keeping the details of the data formats a big secret, requiring thousands of dollars in fees to buy the details, and then imposing a mandatory non-disclosure agreement on anyone who buys the standard, I don't have much hope for their new protocol. It astonishes me that the only open information about NMEA protocols comes from people who have reverse-engineered them.

As an example of a NMEA communication standard, the NMEA-0183 protocol dates, I assume, from 1983. It was only in c.2018 that marine electronic manufacturers got around to using the recommended NMEA-0183 wire insulation colors for their electrical interface connections.

If it took 25-years for an basic element of a NMEA standard to begin to be implemented, image what the future looks iike for an entirely new NMEA protocol.