What data language is bi-directional, multi-transmitter, multi-receiver network?

NMEA 2000.

From the National Marine Electronics Association, NMEA 2000® Interface Standard:

" The NMEA 2000® standard contains the requirements of a serial data communications network to inter-connect marine electronic equipment on vessels. The standard describes a low-cost moderate capacity bi-directional, multi-transmitter/multi-receiver instrument network to interconnect marine electronic devices."

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

Solid detailed info about a cable system in practice is the ODVA company's "Planning and Installation Manual", "DeviceNet™ Cable System." A pdf document.

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How should shielding be grounded on an NMEA 0183 data line?

Terminated to ground at the talker and unterminated at the listener.

Shielding protects transmitted signals from interference, and helps ensure a clear voice sound.

"Talkers" are devices that transmit data such as a compass or GPS, while "listeners" are devices that receive data, such as radar or PC.

For detailed info, please see Continuous Wave Whaler NMEA-0183: Two-pair shielded cable with proper wire insulation colors

Also, please see from Actisense© The NMEA 0183 Information sheet, for excellent and well illustrated info in this area.

From NMEA 0183 Installation and Operating Guidelines and NMEA 0183 Interface Standard

"NMEA 0183 Wiring Requirements NMEA 0183 is a low-cost, low-capacity, single-transmitter/multi-receiver network for interconnecting marine electronic devices, also known as a “single talker/multiple listener” interface."

For concise and comprehensive info, please see Wikipedia's article NMEA 0183

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

The official NMEA site for NMEA 2000 standard.

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What might occur in NMEA 2000 network topology if one device in line should fail?

There will be no interruption to all other devices.

Yes, the system will take the device off the network. But, what if the backbone cable fails, then no network.

For more information, please see Morgans Cloud site, for the article A Fundamental Danger of NMEA 2000 Networks.

Also, please see SeaBits site for the article NMEA 2000 network troubleshooting tools

A major source of info from NMEA.org is the pdf document NMEA 2000© Past, Present, and Future. Please use CTRL-F and search for "fail" or another appropriate word.

Interesting info from Actisense site, article 3 common mistakes when installing NMEA devices.

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

The official NMEA site for NMEA 2000 standard.

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In an NMEA 2000 device, a load equivalence number (LEN) of 1 is equivalent to how much current consumption?

50 mA

It is 0.05 amp or 50 mA. When you add all devices and load, you can determine how much power the network will use. Each device on NMEA 2000© network is supposed to have the LEN rating listed on its plate.

For more info, please see the following: Copper Hill Tech site, for article NMEA 2000© Network Design (Jack Rabbit Marine).

Maretron site for article What is a Load Equivalent Number (LEN), and many technical documents.

Underwater Lights USA site for article What is NMEA 2000 and How Does it Work?

Garmin site for the article How LEN (Load Equivalency Number) Relates to My Device and
NMEA 2000 Network Fundamentals pdf.

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

The official NMEA site for NMEA 2000 standard.

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An NMEA 2000 system with devices in a single location may be powered using this method:

End-powered network.

The backbone of the network has terminators and at one end there is an electrical power feed. The terminating resistors function to reduce the network noise. The goal is to prevent interfering with the data transmissions through keeping the power current separate.

For more info, please see Maretron site for the article Maretron NMEA 2000© Network Installation Guide.

A short, illustrated info from Intellinet Network Solutions, in the article "What is Power Over Ethernet?"

See Artisense site for the article Powering your NMEA 2000 network

Garmin site for the article Garmin NMEA 2000 Network Fundamentals

And, see from Actisense site, a very well illustrated pdf, called The Ultimate Guide to NMEA 2000© Networking.

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

The official NMEA site for NMEA 2000 standard.

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What voltage drop at the end of the last segment will satisfy NMEA 2000 network cabling plans?

1.5 volts

From wp2ahg:

For a 12VDC battery, NMEA 2000 allows a 1.5 volt drop.

(Don't confuse this with the 3.0 volt drop allowed for a 13.8VDC power supply. )

For more details, please see Actisense site article How to calculate a voltage drop

Also, N2KBuilder site, for the article NMEA 2000 Network Design Software User Manual.

The NMEA stands for the National Marine Electronics Association, founded in 1957. The NMEA, or N2K for short, is the agreed upon set of rules (like a common language) for connecting various devices. The system uses an approach from the auto manufacturers, called Controller Area Network, or CAN for short.

For well-illustrated description of NMEA 2000 system, please see KUS USA site for the article
A QUICK GUIDE TO NMEA 2000

Also, please see Wikipedia's article NMEA 2000

The official NMEA site for NMEA 2000 standard.

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