NMEA 2000 CAN Protocol Introduction


NMEA 2000 CAN Protocol Introduction

Introduction to NMEA 2000 CAN Protocol (//en.wikipedia.org/wiki/CAN_bus)
CAN (controller Area Network), a kind of fieldbus, has the advantages of strong anti-interference ability, no concept of address in data communication and unlimited number of nodes, and has been widely used in automobile, ship, CNC machine tool, instrumentation, etc. In 1993, the International Organization for Standardization (ISO) officially promulgated the international labeling ISO11898 for CAN bus, and the protocol layer adopts a modular design approach.

History of NMEA2000

The National Marine Electronics Association (NMEA) was founded in 1957 to strengthen the relationship between electronics manufacturers. In its early years, NMEA focused on improving communications between manufacturers.
Although NMEA 2000 was released in 1994, it was developed in 1999. However, the ship equipment in use is still in a phase of gradual transition from NMEA0183 equipment to NMEA2000 equipment, with NMEA0183 as the main focus and NMEA2000 as a supplement.
For equipment providers, the early upgrade from NMEA0138 to NMEA2000 equipment will take the initiative in the future market.
NMEA2000 is based on CAN2.0B protocol, multiple devices can be connected on one bus, which has many advantages such as high capacity and low cost of laying lines.
In NMEA 2000, in addition to some general PGNs such as network management and device management, different devices support different PGNs, and although the whole protocol is relatively complicated, the functions are relatively simple for very specific devices.


 What is the difference between NMEA 2000 and Ethernet?

Both NMEA 2000 and Ethernet have a role in data transfer, the main difference between NMEA 2000 and Ethernet is that GPS signals are only shared between NMEA 2000, while only Ethernet can share maps. In other cases both share data, such as waypoints, or routes and paths, but both have their own special capabilities, such as Ethernet has the ability to synchronize your devices, share sonar, or map information, while the NMEA2000 can have multiple other plug-ins, such as engine interface readings or fuel flow sensors.