Marine Electronics Communication Protocols and Standards
Modern vessels rely on a complex ecosystem of electronic devices to ensure safe and efficient navigation. For these devices to work together, they must speak a common language. This is achieved through communication protocols—sets of rules that govern how data is transmitted between hardware components on a ship.
While several industry-wide standards exist to ensure interoperability, many manufacturers also develop proprietary systems to enhance specific features of their product lines.
Key Facts
- NMEA 0183 is a legacy serial communication network.
- NMEA 2000 is based on Controller-Area Network (CAN) technology.
- IEC 61162 is the overarching international standard suite for digital interfaces in ship navigational equipment.
- LWE (Lightweight Ethernet) provides a modern, high-speed alternative for marine data.
- Many brands use proprietary protocols, such as Raymarine's SeaTalk or Simrad's SimNet, though many are compatible with NMEA 2000.
Industry Standard Protocols
The National Marine Electronics Association (NMEA) defines the primary protocols used across the maritime industry. These standards allow equipment from different manufacturers to share critical data like GPS coordinates, depth, and wind speed.
NMEA 0183
NMEA 0183 is a serial communication network. It typically utilizes RS-422 electrical standards and transmits data as ASCII serial text. It is generally a simplex system, meaning data flows in one direction.
NMEA 2000
NMEA 2000 is a more advanced technology based on a CAN bus (Controller-Area Network). Unlike its predecessor, it is a duplex system, allowing two-way communication. It uses SAE J1939 binary encoding and typically employs 5-pin A-coded M12 screw connectors with 120R termination.
Lightweight Ethernet (LWE) and IEC 61162
To modernize ship communications, the International Electrotechnical Commission (IEC) created the IEC 61162 standards suite. This comprehensive framework incorporates NMEA 0183, NMEA 2000, and Lightweight Ethernet (LWE) to standardize digital interfaces for navigational equipment within a ship.
Proprietary Manufacturer Protocols
Beyond the universal standards, various suppliers have developed their own communication methods to optimize their specific hardware ecosystems.
- A+T Instruments: Uses ESP Ethernet over Ships Power.
- B&G: Utilizes FastNet.
- CZone: Developed by Mastervolt.
- FDX: Used by Nexus.
- SeaTalk / SeaTalkNG: Developed by Raymarine.
- SimNet: Developed by Simrad.
- Dataline: Used by Stowe.
It is important to note that some brand names refer to product families rather than protocols. For example, Furuno's NavNet is a product family; the actual communication is handled via industry-standard NMEA 0183, NMEA 2000, and standard Ethernet.
Comparison of Marine Communication Standards
The following table summarizes the technical specifications of the most common marine protocols.
| Protocol | Electrical Standard | Type | Simplex/Duplex | Compatibility/Notes |
|---|---|---|---|---|
| NMEA 0180/0182 | RS-232 | ASCII serial | Simplex | Legacy |
| NMEA 0183 | RS-422 | ASCII serial | Simplex | 4800baud 8N1 |
| NMEA 2000 | CAN bus | SAE J1939 binary | Duplex | IEC 61162-3, 250kbs |
| SeaTalk | RS-422 / CAN | ASCII / Binary | Simplex / Duplex | Raymarine |
| SimNet | CAN bus | SAE J1939 Binary | Duplex | Simrad / NMEA 2000 |
| Signal K | Ethernet / WiFi | HTTP | Duplex | Modern Web-based |
| NMEA OneNet | Ethernet / WiFi | - | Duplex | High-speed |
Frequently Asked Questions
What is the difference between NMEA 0183 and NMEA 2000?
NMEA 0183 is an older, simplex serial communication network using ASCII text. NMEA 2000 is a modern, duplex CAN bus system using binary data, which allows for faster, two-way communication between devices.
What is IEC 61162?
IEC 61162 is a suite of international standards created by the International Electrotechnical Commission that encompasses NMEA 0183, NMEA 2000, and Lightweight Ethernet for ship navigational equipment.
Is NavNet a communication protocol?
No, NavNet is a product family from Furuno. The devices within the NavNet family communicate using standard Ethernet, NMEA 0183, and NMEA 2000.
What are some examples of proprietary marine protocols?
Examples include Raymarine's SeaTalk, Simrad's SimNet, Mastervolt's CZone, and B&G's FastNet.
What is the role of Signal K in marine electronics?
Signal K is a modern protocol that utilizes Ethernet and WiFi via HTTP to facilitate data exchange between marine devices.