A great idea to write yourself a paper; but there are a lot of errors in it. I'm not an engineer
, but I'll try to help:
1. 0183 is based on an old serial
data protocol -- EIA422, which means that 0183 equipment is compatible with RS422 ports
. It is a point to point protocol, which means any given port can either talk or listen -- it is not an exchange of data like N2K. You can have only one talker connected to any given listening port at one time, but you can have several listeners connected to one talker. 0183 is sort of compatible with RS232 ports
commonly found on old PCs. To get around the point to point issue and create a true network, you can use a multiplexer, which is able to combine the data streams of several 0183 talkers into a single
data stream. 0183 was issued in several revisions, which are not entirely compatible with each other. Among other things, there are different data rates available, and you have to be sure that talkers and listeners connected to each other are set to the same data rate, and use compatible revisions of 0183.
2. B&G certainly do not use SeaTalkNG -- B&G in fact doesn't exist -- the company was bought some years ago by Navico
, and so now all the consumer-grade B&G gear
is just rebranded Simrad, sometimes (like in the case of the Zeus) with extra software
. Older Navico
gear uses Simnet connectors (which a lot of people think are superior to DeviceNet), but some years ago Navico abandoned Simnet and has been delivering all of its gear with standard DeviceNet connectors. Lowrance is another brand of Navico, the "budget" brand, and most Lowrance gear is also rebranded Simrad.
3. Your ideas about "spurs" and backbones are flawed. Everything is connected to the backbone, and you can connect any device anywhere, including at the ends (as long as there is a resistor terminator). The individual devices are connected with "drop cords" or "drop lines" into "T"-connections in the backbone -- they're not called "spurs". You can connect any device of any type anywhere; you just have to be careful to avoid too much voltage drop -- Maretron makes a free and excellent program to design an N2K network and calculate voltage at each device. The NMEA2000 protocol forbids "daisy-chaining" where devices are connected to each other rather than each directly to the backbone, but this does work in many cases, and some manufacturers have made devices intended to be connected like this.
4. The above is subject to a couple of tricks, courtesy of Maretron -- you can buy a "multiport box" which allows you to connect four devices to one box which has a single
connection to the backbone. In lieu of daisy-chaining, which is forbidden. You can also buy from Maretron a network interface which allows you to divide a large network into multiple sub-networks. This is useful if you want to power down part of your network at anchor
, for example, or to avoid voltage drops over long distances.
5. You can connect 0183 devices to an NMEA2000 network with adapters. My favorites come from Actisense and are inexpensive. These devices translate the 0183 datastream into N2K PNG's. Some of them will even do the reverse translation, so you can get certain N2K data onto a device which receives only 0183.
6. Many plotters will bridge data between N2K and 0183 networks, and this can be really useful. Some data, like AIS
data, doesn't always work well on N2K, and some devices -- like my Airmar CS4500 ultrasonic log -- don't speak N2K. Furthermore, you will 0183 output to feed data to your VHF
, and any other devices which need 0183 position and GPS
data for DSC
I hope that is helpful.
I can't really speak about SeatalkNG, as I haven't used it, but SimNet is 100% compatible in every way with N2K. I have a few devices which use it. You just use an adapter cord and Bob's your uncle.
Concerning compatibility between different makers on a single N2K network --
My experience is that most N2K gear is mostly compatible, but with some caveats:
1. For an "x" brand pilot you will need an "x" brand controller, period.
2. Not all N2K equipment will accept all network commands from equipment of different brands. I've had trouble getting Maretron equipment to accept data source commands from Zeus plotters, for example. Plus not all N2K equipment gives you full control over such things. Source conflicts can be a big problem in my experience, and even small networks these days will have multiple sources for certain types of data.
3. Don't forget the issue of setup and calibration. Usually you cannot setup or calibrate an N2K device from one manufacturer with a device from another. Sometimes you can use a computer for this (Airmar gear can all be set up using WeatherCaster software
, for example) but for that you need a USB gateway to connect your computer.