NMEA 0183 – Complete guide to marine communication and integration

Explore NMEA 0183 – How the standard works, common sentences, and its importance for modern marine electronics.

NMEA 0183 is an international standard that enables communication between marine electronic devices. It is used by everything from GPS units to autopilots and fishfinders and is a cornerstone of modern marine electronics. In this guide, we explain what NMEA 0183 is, how it works, common sentences, and why the standard is so important for boat owners and installers.

What is NMEA 0183?

NMEA stands for National Marine Electronics Association. Standard 0183 defines a common language that marine devices use to exchange data. This allows products from different manufacturers to work together without compatibility issues.

How does NMEA 0183 work?

NMEA 0183 uses a serial communication protocol where data is sent as text strings, called sentences. Each sentence begins with a $ character and ends with a checksum to ensure data integrity.

Example of an NMEA 0183 sentence:

$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47

This sentence contains GPS position, time, latitude, longitude, and altitude.

Common NMEA 0183 sentences and their meanings

Here are the 10 most common NMEA 0183 abbreviations:

• GGA: GPS fix data
• GLL: Geographic position (latitude/longitude)
• GSA: GPS DOP and active satellites
• GSV: GPS satellites in view
• RMC: Minimal navigation information
• VTG: Track and ground speed
• ZDA: Time and date
• HDG: Magnetic heading, deviation, and variation
• HDT: True heading
• DBT: Depth below transducer

Why is NMEA 0183 important?

The standard enables interoperability between devices from different manufacturers. A GPS from one Brand can communicate with an autopilot from another, providing flexibility and easy integration into marine systems.

How to connect NMEA 0183 devices?

1. Direct connection: Connect devices with NMEA 0183 cables.
2. Multiplexer: Collects data from multiple devices to one receiver.
3. Gateway: Converts NMEA 0183 to NMEA 2000 for modern integration.
4. Isolation: Protects against ground loops when connecting to a PC.
5. Battery banks: Ensure correct negative pole connection to avoid interference.

Differences between NMEA 0183 and RS422

NMEA 0183 now uses RS422 differential drive for better interference protection and longer cable lengths. Originally, it was single-ended, but was updated to meet modern requirements.

The future of NMEA 0183

Although NMEA 2000 is taking over with higher speeds and more features, NMEA 0183 will continue to be relevant for older systems and simpler installations for many years to come.

See the complete list of NMEA 0183 abbreviations here.