Ethernet and NMEA-2000 are now well established standard communications protocols, both being buses (multiple devices connected together that allows them to communicate to each other).
Ethernet is the ‘big pipe’. It has lots of bandwidth, allowing the distribution of large amounts of data including real-time graphics. It also can extend communication to the outside world, allowing access to data off the Internet. Ethernet can also go wireless (WiFi), cutting the cord to some of the devices.
NMEA-2000 is a sensor bus based on automotive technology. This gives sensor manufacturers a broader market by standardizing access across the instrument market, reducing the cost to the customer. It is not fast enough to distribute graphics and does not extend outside the boat.
These two buses pretty much put the kibosh on the various proprietary instrument buses out there.
Moore’s law has worked its magic for 20 years since the advent of digital instruments, pushing more computing power into the processor and the displays. Instrument processors can now do more stuff, and displays can display more information and be given control responsibility.
Graphics communicate much more information on a single display than multiple numeric displays, allowing you to determine what’s going at a glance instead of reading some numbers and trying to figure out what they mean.Two examples of how graphics are useful are chart plots and stripcharts. Graphical displays do require wide bandwidth communications and greater computational power.
Graphical displays come in many forms, e.g. smartphones, tablets and marine monitors. Their cost covers a wide range, and there are many specs that need to be determined. Because of this change in flexibility, the display choice must now become independent of the instrumentation choice. Learn more…
The Ockam solution
The consequence of these technical advances on the Ockam system design are;
- The processor needs to communicate over Ethernet and NMEA-2000.
- Ockam interfaces are obsoleted by NMEA-2000.
- Creating proprietary graphical displays is no longer economically feasible because of the available alternatives (read more).
The latest generation of the Ockam system has addressed these issues.