DSC, GPS and protocol conversion

[Meriachee]

The Raymarine guys are suggesting the use of an Actisense protocol converter when wiring a NMEA0183 device to the STng network.
Without going into the specifics of a long, drawn out, and quite frankly incorrect directive by the radio guys, (company name withheld as it could be anybody) I would suggest to anybody thinking about adding a device requiring gps, like a DSC radio, that you consider carefully the requirements before selecting the device.
I can state that the time spent trading diagrams, and the need to build connectors for the inevitable firmware, and the fact that almost three months after this little project started (I mean really, there's only FOUR wires, how freakin hard does it have to be) the gps input to the radio and AIS output from the radio is still not working.

The takeaway from all of this is that in the case of anybody installing a new radio with DSC, give some serious weight to embedded GPS over a pair of wires that get hooked up to an external GPS. Networks are interesting, but the lack of standardization across the board is a real pitb. I get to do firmware all day, and the growing list of devices on the boat is disconcerting.

Cheers
Gary

 

[BarryL]

Hey,

Some more specifics would be helpful. Maybe there are products and / or vendors to avoid.

My last boat had a Lowrance plotter (LMS 337) and a Standard Horizon GX2100 radio. I had no problem getting the plotter to send GPS info to the radio using NMEA 0183. I was also able to get the radio to send AIS data to a laptop via a serial port.

On my current boat I just installed a Garmin GPSMAP 740 plotter, Rayramine EVO 100 wheel pilot and Simard RS 35 VHF. All are either STNG or NMEA 2000. To connect the instruments all I needed to do was connect the NMEA 2000 cables. No looking at little wires, no soldering, crimping, or anything. I bought two NMEA 2000 to SeaTalk NG converter cables (for the Garmin and Simrad gear) and then connected them to the Seatalk backbone with T connections. Once I had pulled the wires it took less than 5 minutes to get them all talking. The plotter can display AIS targets, the VHF gets GPS information, the AP can navigate to a waypoint, etc.

Barry

 

[Stu Jackson]

The takeaway from all of this is that in the case of anybody installing a new radio with DSC, give some serious weight to embedded GPS over a pair of wires that get hooked up to an external GPS. Networks are interesting, but the lack of standardization across the board is a real pitb. I get to do firmware all day, and the growing list of devices on the boat is disconcerting.

Gary,

I hear ya. This has been a recurring issue on this and other boating forums for many, many years. As Barry said, however, some systems play better with others, just like the kids in the playground!

Nowadays, Standard Horizon, among others, is making integrated units, things I and others have been promoting as "A Basic Smart Boating Thing To Do" for many, many years.

Why didn't they do this before? Simple, they could sell two or three separate units (VHF, GPS, AIS) rather than one. Now that the costs of the chips are "sunk costs" they can begin to offer integrated units, which make incredible sense.

Now, here's another one that I've mentioned before:

Why do they stick integrated AIS in a blinkin' VHF radio?!? You can't read the screen. They should be offering integrated AIS inside the darned chartplotters, for goodness sake! VHF can be separate, never needed AIS inside. GPS in a VHF makes sense for DSC.

What do you think?

 

[Jackdaw]

Rare is a plotter (even new ones) that does not have at least one old-school NMEA0183 output. Our new-ish Lowrance HDS-8 touch does.... its only purpose in life is a direct-wire run to the NMEA0183 inputs on our DSC radio.

 

[Jackdaw]

Gary,



Why do they stick integrated AIS in a blinkin' VHF radio?!? You can't read the screen. They should be offering integrated AIS inside the darned chartplotters, for goodness sake! VHF can be separate, never needed AIS inside. GPS in a VHF makes sense for DSC.

What do you think?

Stu, because from a hardware perspective, AIS IS a blink' VHF radio. Almost everything inside is dual-purpose. I agree that the end-user (AIS) functionality belongs in the plotter.

 

[Meriachee]

stupid DSC

I don't mean to wax philosophical, but I agree that this stuff -should- be easy. Having built a few (thousand) microcontrollers and living in a software world where hourly firmware updates are quite normal, the pleasure of going to the boat was somewhat removed from that. Having all this cool stuff displayed right there on the binnacle, and seeing an incoming DSC GPS target on the plotter and being able to calculate a route, blah blah. The downside is that there's all the Ray stuff, a65, 2-i70s, p70/spx5, itc5, dst800, wind, water temp, latest updates from Wall St, but there's also the NoLand RS11 watching the trusty Westerbeke, and now there's this Actisense converter. ALL of which requires firmware, each of which has a different format for that firmware and none of it speaks to any other part of it without prompting/cajoling.
I have, right now, on my desk six (6) completely different connection diagrams for the Actisense and the GX2150. FOUR wires. (!) (I'm apparently to wait for the other 10 possibilities to arrive and then pick one) The Standard book is wrong, apparently. The Actisense book is subject to interpretation. The diagram that was garnered from Ray, in the forums, is the most wrong. The Standard support desk thinks there's an issue with my "gps unit" but their book is right.
An email train from Actisense this morning has laid out the matter in much clearer terms, which I will try when I get out to the boat. It also includes a note to suggest that the current firmware addresses a lack of AIS data, and do I have a connector that I can wire (solder) to their board so I can download the firmware and driver software.
I do this crap for a living and this has me baffled. How could a guy who can barely spell DSC ever get something like this to work? (and that's not to take ANYTHING away from the guy who'd rather cruise than spell DSC)
Good thing we normally live on an inland lake and the thunderheads and pelicans don't show up as AIS targets. All this nonsense because the freakin radio beeps every couple of hours because it wants GPS input for the stupid DSC. That's my new mantra. 'stuipd DSC'

Cheers
Gary

 

[Meriachee]

Gary,

I hear ya. This has been a recurring issue on this and other boating forums for many, many years. As Barry said, however, some systems play better with others, just like the kids in the playground!

Nowadays, Standard Horizon, among others, is making integrated units, things I and others have been promoting as "A Basic Smart Boating Thing To Do" for many, many years.

Why didn't they do this before? Simple, they could sell two or three separate units (VHF, GPS, AIS) rather than one. Now that the costs of the chips are "sunk costs" they can begin to offer integrated units, which make incredible sense.

Now, here's another one that I've mentioned before:

Why do they stick integrated AIS in a blinkin' VHF radio?!? You can't read the screen. They should be offering integrated AIS inside the darned chartplotters, for goodness sake! VHF can be separate, never needed AIS inside. GPS in a VHF makes sense for DSC.

What do you think?

I think as I always do. SIMPLE Stick a freakin ethernet plug in the back, build a small, power-cheap switch, and hook the stuff up. None of this 0183, 2000, CANbus, read: 'proprietary network' junk. The stuff all talks, and the public should speak up loudly to make the manufacturers do the same. (and yes I completely understand that an RJ45 jack in a binnacle ain't gonna work for long, but you get my point.) Ethernet. Standardize the communications and connections to a marine environment, and have a nice day. Fix your software if it doesn't conform. Why can't I, as a consumer, simply plug a device into the network as long as it conforms. You plug your laptop into the network at the office. I plug my phone system into the network. None of this causes a great glowing orange hole in the ground anymore, so why do we have to put up with it on the boat. (I know why, but I'm just sayin)

 

[Meriachee]

collision avoidance

Hey,

Maybe there are products and / or vendors to avoid.

Barry

Barry,

Sorry, I'm not going to get on a soapbox and start a run on products to avoid. The whole issue is the network. (and my new mantra, "stupid DSC")

Cheers
Gary

 

[Stu Jackson]

Gary,

stupid DSC is a good mantra.

Just to add: given your background and well described experience in the real world (thanks, that WAS great stuff), it is appalling that the vendors "think" they've solved the issues. Their marketing has exceeded the ability of their engineers, or they haven't listened to the engineers (more likely), and tech support has no clue 'cuz no one wrote the "How to really use this stuff" manual, or if they have, it never got translated or poorly translated to the printed manual.

A repetitious but not unusual (dammit) pattern of production of a most products by big industry.

There still are some smaller vendors who actually make a good simple product with a manual that explains the how and the why.

OTOH, there's the issue of "perceived advantages" of system integration, which, by all rights, is a completely separate subject, another one of which I have suspiciously vigorous opinions which I'm willing to share if anyone cares. :cussing::cussing::cussing:

This topic would be a perfect lead-in for that, huh? :dance:

 

[tommays]

Quite Simply 0183 alone it is really OLD and at BEST has many versions

The NMEA is so weak that everyone can intentionally NOT follow the standard to force you into one brand

 

[Meriachee]

Stu,
I do believe in the "captive" network. (I've consumed the koolaid) There are advantages, and overall, this is not rocket science stuff. Where it fails (miserably in my experience) in the marine environment is that nobody is willing to take ownership of the issues. Case in point; I've got three vendors pointing fingers at each other over a serial port. It's 1970's technology people, why does it have to be this hard. The answer of course is manufacturers like Ray who insist on having variants on their network. It's IN HOUSE stuff, but you see posting after posting on the tech forum of "this Ray device won't work with that Ray device", because this device is ST11 and that device is STnw or some other stupid thing. Nortel used to call it "evergreen", wherein, any device from the Enterprise product line would work. I've plugged line cards from 1980 into a new switch and they work. That is so cool it's almost comforting. The newer IP stuff works hand in hand with digital and (gawd forbid) Analog, and now it all works with SIP. The backbone changes, but the front end support is still there.
Who gives a rats rear end what the DSC "says" or listens for. It's the "how it gets there" that is the issue.
stupid DSC

cheers
Gary

 

[Bill Roosa]

I would note that the Raymarine ST1, ST2 and STng ARE compilable is you simply use the conversion cable from Ray. AND the STng is just a super set of sentences on the NMEA2000 standard. That means STng can be attached (with appropriate cable) to a MNEA2000 network buss. The Ray ST protocol is a standard 8 MHz, 2 wire, many talker, many listener, IEEE protocol. FWIW