In Finnish – suomeksi
In the industrial internet the idea is to combine a variety of intelligent devices to each other and make the data available in the network. The automated data collection, sharing of the data and refining of the data enable new applications and services that create value for the users.
Electronic devices used in vessels (eg. compass, log, radar, depth sounder, VHF radio telephone, satellite tracking, engine gauges) were practically until the end of the 80’s completely isolated stand-alone devices, that had their own independent user interface. Any data collected by the device or data processed by the device could not be shared otherwise than manually by the user.
US Marine Electronics Association (National Marine Electronics Association) started to develop in the early 80’s a standard for transferring data from one device to another. Equipment manufacturers adopted the NMEA0183-standard world wide and it was the basis for a global marine electronics interface standards IEC61162. NMEA0183 (IEC61162-1 and IEC61162-2) are technically very simple and reflect the technology that was commonly available at that time. The standards define text messages and their transfer with serial communications (RS-422 or RS-232) with 4800 or 38400 bit/s. The units can be connected in such a way that two devices interact talking and listening. However, on the same serial bus you can have several listeners, but only one talker. If there is a need to have more than one device to transmit information you need several serial buses or a separate multiplexer, which combines several talkers on the same serial bus, preventing them to talk at the same time. Installing sensors and devices with NMEA0183 may be difficult and time consuming requiring a lot of testing and trials especially if there are many sensors and devices.
NMEA2000 (IEC61162-3) is a newer standard for marine electronics. It is based on CAN-bus standard (ISO11898) used in vehicles and industry and the upper protocol layers comply with the SAEJ1939 standard added with definition for marine electronics messages. On NMEA2000 bus all the devices can talk with each other. Connected sensors and devices form a network. The data transfer rate is 250 kbit/s. Marine electronics manufactures have often a brand for their own NMEA2000 (eg. Raymarine SeaTalkNG, Simrad SimNet, Furuno CAN) and the plugs and cables may be different. Installation of NMEA2000 sensors and devices is simple and straightforward. The devices from various manufacturers will work nicely together in the same network.
NMEA OneNet is the next step in marine electronics data transfer standardization. The data rate in NMEA2000 network is not enough for example transferring the radar sensor image on a screen. NMEA OneNet is based on the Ethernet standard (IEEE802.3). The data transfer rate is from 100 Mbit/s to 10 Gbit/s. The manufacturers intend to standardize the transfer of NMEA2000 messages in Ethernet and interfaces to NMEA2000 network. The standardization work is still in progress and today’s devices use proprietary protocols for Ethernet data transfer.
There is also a need for an open marine electronics data transfer standard. Signal K development group has a vision and an implementation, where the data from the NMEA network moves easily to different equipment and applications – even ship to ship or ship to shore
Industrial Internet or IoT will certainly enable new applications and value creation for boaters.
Jukka Wallinheimo
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