iKommunicate and the Smart Transducers

Airmar Smart Tdxs

Recently we have seen a trend in customers asking about using smart transducers with our iKommunicate, rather than installing the more traditional; Log, Depth, Wind and navigation instruments.

If you are re-fitting an older boat or doing an install on a new boat, then it is worth considering the cost benefits and simplicity of design that this approach provides. Whether you create an NMEA2000 backbone or simply wire together NMEA0183 cables, having iKommunicate receive all of the transducer data and then distribute this over a wired or wireless Ethernet network, where the data can be displayed on multiple tablets, phones or computers around the boat is very desirable.

One of the most common questions is…”What transducers should I use?” and so we thought we would tackle this question in this article.

When it comes to transducers, the leading player by a mile, is Airmar the US company that manufacture transducers for pretty much all of the big players in marine electronics. As a result, their product catalogue is massive and finding the right model and part number can be pretty daunting and time consuming, so we have tried to highlight the ideal transducers in their range for using with iKommunicate and listed the Gemeco Part Numbers (SKUs) who are Airmar’s US distributor and whose website is very informative.

The obvious “through the hull” Speed and Depth transducer for most yachts and powerboats, would be the DST800. Described as a “Triducer” as it has a Speed, Depth and Temperature sensor, the DST800 is fully retractable for cleaning, with an integral valve that significantly reduces water ingress. It is available in Plastic, Bronze or Stainless Steel, with both NMEA0183 or NMEA2000 versions.

The NMEA0183 version, which can be used on 12v or 24v systems, comes with 10m of cable, terminated in bare wires and you simply add an S to the end of the part number for this version i.e. DST800PV-S.

The NMEA2000 version, powered from the NMEA2000 network, comes with 6m of cable, terminated in the “standard” male NMEA2000 connector (same one as iKommunicate) and for this version you simply add N2 to the part number i.e. DST800PV-N2.

Gemeco SKU Description
DST800PV-S NMEA0183 – 235kHz Smart Triducer – Plastic
DST800BV-S NMEA0183 – 235kHz Smart Triducer – Bronze
DST800SV-S NMEA0183 – 235kHz Smart Triducer – Stainless
DST800PV-N2 NMEA 2000 – 235kHz Smart Triducer – Plastic
DST800BV-N2 NMEA 2000 – 235kHz Smart Triducer – Bronze
DST800SV-N2 NMEA 2000 – 235kHz Smart Triducer – Stainless

So with the DST800, you get Speed (through the water), Depth and water temperature, plus as a bonus a distance log as well, which just leaves the Wind to worry about.

With the Wind transducer Airmar really “threw away the rule book” for designing Mast Head Units by removing all moving parts and using ultrasonics to measure wind angle and speed. Although not ideal for every type of boat, the 120WX and 220WX Weatherstation® instruments are really good bits of kit which not only measure the wind, but also air pressure and air temperature and in the case of the 220WX, with integral GPS and Compass sensors, even your position, heading, rate of turn and attitude (pitch and roll).

Above is an image of the 220WX which is physically identical to the 120WX.

Both units have NMEA0183 and NMEA2000 built-in, so no different versions to worry about, you simply order either a WS-120WX or WS-220WX and specify the type and length of cable you need;

Gemeco SKU Description
WS-C10 NMEA0183 – 10m
WS-C25 NMEA0183 – 25m
WS2-C06 NMEA2000 – 6m
WS2-C10 NMEA2000 – 10m (Terminated)
WS2-C30 NMEA2000 – 30m (Terminated)

There are other lengths available but we have listed the most popular for Yachts and Power Boats. The two NMEA2000 cables that have (Terminated) after them, include the NMEA2000 termination resistor and must be mounted at the end of the NMEA2000 network.

Should your budget not stretch to an ultrasonic wind transducer or you prefer a more traditional mast head unit, then our own WND100 wind transducer which comes with a 20m NMEA0183 cable is well worth considering, perhaps coupled with our HSC100 smart heading sensor and GPS150 Dualnav position sensor both of which have NMEA0 183 outputs to connect to one of the three NMEA0183 inputs on iKommunicate.

So you have your iKommunicate and smart transducer setup, but what options are there for displaying the data? Well you have plenty of PC Navigation packages; Nobeltec, Rosepoint, Fugawi, Seapro, MaxSea, SmarterTrack, etc. and then Apps like NMEA Remote, iSailor, iNavX, iRegatta, SailRacer, TimeZero, Imray etc are perfect for running on your Apple iPhone/iPad or Android phone/tablet in the cockpit. If you want a dedicated display then perhaps a single graphical display from Garmin, Raymarine, Simrad, etc. or a mast display from NASA or Race Geek would give you a permanent cockpit display without breaking the bank.

Finally with iKommunicate you also have the option of running the new Signal K web apps in your browser so any mobile wireless device can display the data on a modern web browser, even a Kindle !

 

New iKommunicate Developer’s Guide (SDK)

iK GitHub Site

This week we launched a new iKommunicate Developer’s Guide on GitHub that aims to make it easy for developers to start writing HTML5 Web Apps or mobile Apps that read data from NMEA networks via the new Signal K open data format.

iKommunicate is designed to be a powerful and intelligent gateway that efficiently converts NMEA data in to Signal K data, but that is just half of the jigsaw. The other key elements are the apps and software that work with iKommunicate to make it a fun and useful addition to your boat.

Out of the box, iKommunicate will work with all Navigation Software packages and Apps that support NMEA network data over TCP or UDP and it will also include a couple of Signal K web apps to get you started. However, it is hoped, that as more and more developers realise the potential of Signal K, that a plethora of innovate and useful apps will start to appear, transforming the way we use out boats.

In putting together the Developer’s Guide, we realised just how easy it is to start developing apps and there is an awful lot of information, libraries and source code on the internet that you can draw upon as you become more experienced. Even if you have never looked at HTML5, http REST APIs or WebSockets, our wiki and example apps, will give you a good starting point and have you displaying Signal K data in no time.

Testing NMEA0183

NMEA Display Program

Back in the 1980s the National Marine Electronics Association (NMEA) defined an interfacing standard that would revolutionise the way marine electronics operated together. For the first time a common standard was defined that allowed equipment from different manufacturers to talk to each other and do things that had previously been impossible.

After a few iterations (NMEA0180 and NMEA0182) the NMEA0183 standard was published and gradually manufacturers developed products that had NMEA0183 Inputs and Outputs that could be connected together. There were some teething problems but over time NMEA0183 established itself as a very compatible and reliable interface standard and even today most marine electronic systems have at least one NMEA0183 interface, although the newer NMEA2000 standard is gradually taking over.

Online information on NMEA0183 is fairly limited and often quite old, but Actisense publish a useful booklet on NMEA0183 and this website http://www.catb.org/gpsd/NMEA.html has also collected a lot of useful information on NMEA0183.

Testing NMEA0183 systems can be done in a number of ways. The simplest method, just to see if there is data being transmitted or not, is to place an LED across an NMEA0183 output. One way round the LED should flash and the other way round it will not flash. If the LED fails to flash in either direction then no NMEA0183 data is present. For more information on this type of LED test, please download our Tech Note by clicking here.

If after establishing that there is NMEA0183 present, you wish to go a step further and look at the raw data to see what messages are being transmitted then you will need an old laptop and an NMEA to USB adaptor cable like our Part# ZDIGUSBNMEA. This adaptor cable can easily be connected to any NMEA0183 Output (two wires) and then with suitable software running on the PC, the NMEA0183 data can be displayed and interpreted.

USB_NMEA_Serial_Adaptor_Clear

A few years ago, when Microsoft stopped including a utility called HyperTerminal in Windows Vista/7/8,  Digital Yacht developed a useful NMEA Display program that is free to download from here.  Our NMEA Display program is perfect for not only viewing the raw NMEA0183 data but also for interpreting and displaying the different fields of data i.e. Wind Speed, Depth or Heading. For more information on using this program and NMEA0183 in general, please refer to an earlier post we wrote, by clicking here.

With these simple tools and techniques, anyone can test and fault find NMEA0183 systems and with so many systems out there, it is a useful “string to your bow” that might just get you out of trouble.

Testing Wireless NMEA Data

iAIS TCP-IP Screen

 

With more and more wireless NMEA systems being installed on-board boats, it is very useful for dealers, installers and enthusiastic end users to have simple tools to “view” this wireless NMEA data.

Traditionally, wired NMEA0183 data was viewed using an NMEA to USB cable connected to a PC and then a program such as Hyperterminal (included with Windows up to WinXP) would be used to display the data. In fact Digital Yacht released a free, dedicated NMEA Display program to use on Windows Vista/7/8 and this proved to be a popular tool for testing wired NMEA0183 systems.

With wireless NMEA systems it is much easier to test using a smart phone or tablet and we would recommend the following free apps;

For Apple iOS Devices – our own free iAIS app (see image above) has a very simple raw data view window that can be used to display the wireless NMEA data in TCP or UDP mode. Alternatively iNMEA Logger is another free app, written by the company that developed the popular iRegatta App that can log 30 seconds of received data and create a text file of the results, useful if you do not understand NMEA0183 and want to send it to someone who does.

For Android Devices – there are no specific wireless NMEA Apps, but there are a lot of terminal programs that display TCP and UDP data and after trawling through a fair number of apps, we came across TCP/UDP Terminal App which we think is the best Android App found so far.

Once you have installed your app for displaying wireless NMEA data, then you need to know what you are looking at. To buy the NMEA0183 Specification costs quite a lot of money but there is quite a lot of data on-line, you just need to hunt it out.

Unfortunately a lot of the information on-line is quite old and some of the newer sentences are not fully explained. The NMEA do in fact publish a complete list of all Sentence Identifiers with a short description of what they are (not the complete sentence description) and this list also includes the proprietary Manufacturer’s ID – these sentences start $Pxxx, where xxx = the manufacturer identifier.

It should be noted that most wireless NMEA data is “human readable” (ASCII Text) but the AIS sentences VDM and VDO have what is called a “binary encapsulated” section (bit like a zip file) to reduce the sentence length – see example below.

!AIVDM,1,1,,A,13P;QeO001wrdB`M28kpmCa<0Ua0,0*5D
!AIVDO,1,1,,,B00000@00ovdqaWAUv“CwkUsP06,0*20

This means that you will not be able to make sense of the AIS target information in the VDM and VDO messages, but our free iAIS app does display this information on the main plotter screen, so worth having a copy of this app.

Using Digital Yacht USB products with OpenCPN V3.2 or higher

Workspace 1_020

In the first of two posts about using our products with OpenCPN, we are pleased to announce the release of a new Tech Note that provides OpenCPN (Windows/Mac/LINUX) users with a clear guide on how to configure the latest Connection Manager (in OpenCPN since V3.2) to work with our USB products.

OpenCPN is one of the most popular marine navigation software packages and is completely Open Source, meaning that Windows, Mac and LINUX users can install and use the software for free. For more information on OpenCPN please click here.

If you have one of our AIS, GPS or Interfacing products that has a USB interface and you want to use it with OpenCPN, then please download Tech Note 00061-2014 by clicking here.

The Non-Idiot’s Guide to AIS

Non Idiots

We had an enquiry today from a US Dealer about why some chart plotters do not display all of the 26 different AIS Messages that are transmitted by Ships, AtoNs, AIS MOB systems and other AIS equipment. This is quite a complex issue as there are three variables at play….

1) The AIS transponder or Receiver

Most AIS receivers and transponders support all AIS messages, however it is true that early Class A and some receiver only units do not support all AIS messages. It is always best for the owner of older AIS units to check that they have the latest firmware in their units and to even contact the manufacturer to see if their unit supports the more recent AIS messages like AtoNs and AIS SARTs (MOB) systems.

The good news for Digital Yacht customers is that every AIS unit we have ever sold supports all of the 26 AIS messages currently defined.

2) The Chart Plotter or Software Application

Even if the AIS transponder or receiver is compatible with all 26 messages, it does not necessarily mean that the chart plotter or software application (running on PC, iPad, etc.) knows how to read and display the AIS messages.

When AIS was first released, many manufacturers and software developers just did a partial AIS implementation, only supporting what they considered to be the most important AIS messages. Also due to delays in the definition of Class B transponder messages, some of the manufacturers only supported the display of Class B targets but not the reading of the Class B static data (boat name, boat type, etc.). Even large manufacturers like Raymarine, Navico and Garmin took a few years to release new firmware for their plotters to improve the number of AIS messages that they supported.

3) NMEA2000 PGNs for AIS

Due to delays in the NMEA committee defining PGNs for AIS, some plotters only support some of the 26 AIS messages when connected via NMEA2000, even if they support all 26 messages via NMEA0183. This Panbo article provides more info on this issue.

http://www.panbo.com/archives/2012/06/ais_over_nmea_2000_the_shame_sheet.html

To help the dealer better understand some of these finer points of the AIS system, we sent him a copy of our Non-Idiot’s Guide to AIS that we produced for the British Marine Electronics Association.  The 26 AIS messages are detailed on page 12 of this document and the NMEA2000 PGNs are on page 13.

This presentation is a few years old now but is still a useful reference for anyone wanting to learn a bit more about AIS technology. To download a copy click here.

NMEA Meeting in Gosport

NMEA Committee

The National Marine Electronics Association (NMEA) as the name suggests is a trade association of nearly 600 companies involved in marine electronics. The NMEA organisation are responsible for a whole series of important specifications and training initiatives that have significantly improved the marine electronics industry.

Probably best known for their work on the NMEA0183 and NMEA2000 communication specifications, the NMEA have a series of committees comprised of volunteer industry experts who regularly meet to define new specifications and update existing ones. The most recent meeting took place this week in Gosport (UK) and our CEO Paul Sumpner joined representatives from Navico, Raymarine, Actisense, Standard Horizon, SRT, Icom, Mercury, Fischer Panda and the US Coastguard to discuss NMEA2000 and the new NMEA OneNet standard.

This meeting was held at the QinetiQ facility, in the old Haslar Naval buildings on the Gosport side of Portsmouth Harbour. QinetiQ are a world leading defense research agency and have the world’s largest marine test tank which they use to model and test different hull designs.

QinetiQ

On Thursday, a “PlugFest” was held that gave manufacturers a chance to test their latest equipment in a large and diverse NMEA2000 network to ensure that all of the equipment worked nicely together, sharing data and commands on the network. The first image above shows the engineers busy at work monitoring the network, fuelled by coffee and Jaffa Cakes !

Steve Spitzer the tireless Technical Director of the NMEA was chairing the meetings, keeping everyone on track as well as recording the discussions and updating the draft specifications in real time – which can be a difficult and thankless task but one that Steve does very well. For more information on the NMEA Organisation and the work they do, please visit their website by clicking here.