Stronger Backbone

The National Marine Electronics Association (NMEA) represents major marine electronics manufacturers such as Furuno and Simrad, as well as marine electronics dealerships around the U.S. 

NMEA also develops technical protocols that help manufacturers and their dealers provide better functionality for the wide spectrum of electronics they sell and install.

One such protocol is NMEA 0183, which allows data from one device to be shared with others. For navigation instruments, the information that can be shared is usually just between devices from the same manufacturer. 

A step up from NMEA 0183 is NMEA 2000, also called N2K. That’s a protocol standard that permits multiple instruments to be run as a network where one device shares and displays information from another device, such as a sensor, gauge or chart plotter.

With N2K, all the instruments are connected to one central cable, the backbone, with drop lines running off it having premolded connectors on the ends that attach to individual electronic devices. The backbone powers the instruments and passes data from one device to any other on the network. It doesn’t matter if the devices are from one or several manufacturers. 

“You can share information all around the boat,” said Hugo Lupo with New England Marine Electronics in Norwalk, Conn. “The engineer can have a display down below and you can see the same information on the bridge. That’s one of the big values, sharing different information from different manufacturers.”

A N2K system can be as limited or extensive as a boat owner desires, using bridge extenders to increase the length of the backbone and gateways to bring data from devices with other protocols, such as a PC, into the NMEA 2000 network. 

A retrofit situation that Lupo recently oversaw involved a Coast Guard buoy tender. “It was one of the old buoy tenders, and we totally digitized the information off that engine.” 

Other than installing a NMEA 2000 backbone and a gateway, nothing was taken off or added to the engine.

“We used existing sensors and digitized every bit of that and put it up on the bridge. They now know what speeds to run for the best economy,” Lupo said.

Currently, New England Marine Electronics is working with the pneumatic system on what Lupo described as “a real old fireboat.” He expects to use the existing pressure gauges and still be able to convert the readings to digitized data. Then “the information will be shared all over the boat,” he said.

In British Columbia, a large tug caught fire at a Vancouver dock “and no one ever heard the alarm,” said Ken Harrison with SummerHill CA Sales in Blue Mountains, Ontario.

The vessel owners, seeking to avoid the same scenario with any of its six other tugs, figured “there must be some technology that can send an alert to our phones,” said Harrison. But they didn’t want to rewire the boat. They wanted to use what was already in place. 

The N2K backbone that Harrison installed was “very small but it serves the needs,” he said. “We haven’t changed any sensors, everything stayed the same. We were just able to get that data and convert it, so alarms get triggered, and it’s out to multiple users.”

It proved to be extremely cost effective. So much so that the other six tugs had their alarms wired into NMEA 2000, Harrison said. 

Today, more and more electronics products are being designed and built to N2K certification standards from inception. 

 

ACCEPTANCE 

NMEA 2000 is still in the process of being accepted in some workboat markets, particularly larger boats. For example, Washington State Ferries vessels “have almost no NMEA 2000 on them at all,” said Keith Ostby with Harris Electric in Seattle, which has radar and several other contracts with WSF.

He attributes this to the larger equipment used on the ferries. The radars are IMO-rated, and “they pretty much want to stay with IMO equipment,” said Ostby.

Even though some large boat operators might not have hopped onto the N2K wagon, perhaps NMEA’s next generation of connection protocols will gather more converts. 

By the end of the year, the association should be releasing an improved standard. It’s called NMEA OneNet and will deliver more information and at a faster rate than NMEA 2000.

OneNet will transmit N2K data using an ethernet protocol with up to 10 gigabits of transfer speed — about 44,000 times the speed of N2K — and more power capacity, as much as 30 watts for each device on the network. 

A big plus for OneNet will be the ability to transmit video. “It will have a big effect because one thing we can’t pass on with N2K — because we don’t have the bandwidth — is video,” said Lupo. “OneNet is the future in the marine industry, right up to IMO. It will have the bandwidth to take care of radar.”

 

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