National Marine Electronics Association
The National Marine Electronics Association ( NMEA ; German National Association for Marine Electronics ) is an American association of electronics manufacturers and dealers in the shipping industry. The association was founded in 1957 and registered as a company in 1969. Its main goals are the promotion of standards and technical developments in marine electronics as well as the technical training of its members.
Standards
The NMEA standard is a transmission standard in the maritime sector that is available in different versions. The main application here is the exchange of navigation data between navigation instruments, such as B. GPS receiver , electronic log , echo sounder , AIS , ECDIS and other devices.
The first version NMEA-0180 from 1980 defined a transmission with 1200 baud . This and version 0182 (published in 1982) only have historical significance.
NMEA-0183
NMEA-0183 (from 1983) works at 4800 baud. This means that backwards compatibility with older versions has been partially abandoned, version 0183-2.3 is no longer fully compatible with old devices. The version NMEA-0183-4.1 has been up-to-date since June 2012.
The 0183 standard distinguishes between devices that send data (“talker”), such as GPS, and devices that receive data (“listener”), such as display devices. While one transmitter can supply several receivers, a so-called multiplexer is necessary to use several transmitters for common receivers . The data transfer takes place in small data units, the NMEA data sets ("sentences"). Each data record cannot exceed 80 characters.
NMEA-2000
The new NMEA 2000 standard is based on the CAN bus and is becoming increasingly widespread. Devices with NMEA 0183 support are still in the majority. The advantages of the new 2000 standard are plug and play compatibility and the 50 times higher data transfer rate. Furuno , Garmin , Lowrance and Maretron adhere to the NMEA 2000 standard. Simrad and B + G used a special NMEA 2000 version with slim connectors and call the network “Simnet”, but with a few exceptions the standard connectors are now used. Raymarine calls its version "Seatalk ng".
Related bus systems in the maritime sector
In addition to the NMEA standards, there are other options for connecting different systems in shipping. So has z. B. Raymarine developed its own system similar to NMEA-0183 with Seatalk . This system is also considered out of date. Another approach was developed with “ Furuno Navnet”, which is closely related to 10 Mbit Ethernet. Also CAN bus systems are, such on the market. B. as "Corus Navico".
Web links
- Website of the NMEA (English)
- All NMEA 0183 sentences (English)
- NMEA-0183 data explanation
- German information site
- Java library for NMEA analysis
- C library for NMEA analysis
Individual evidence
- ↑ NMEA standards ( memento of the original from August 4, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
