Hylas 54 Specifications | Home (Back to home page of website www.Dakare.com)
Integrated Electronics
We aspired to have a Nav Station similar to that on our old Dakare (Slocum 43). At the time the electronics were integrated together (1995-97), it was new, novel and state-of-the-art. Today, it is quite common practice to have shipboard integrated electronics. Based upon our previous experience, we evaluated two different architectures. One was based upon our old configuration and one was based upon using new hardware and software from Raytheon. (* See notes below images.) The two configurations are:
Configuration 1
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1. B&G
2. Furuno
3. Northstar 951
4. Two different Computers
3. Nobeltec's VNS (We were happy with the functioning of their product , even with, in our opinion, their overly burdensome registration process),
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Configuration 2
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1.Bi-directional SeaTalk Network
2.Raytheon Navigator's Active Routing functionality
3 Inclusion of the Northstar 951 GPS
4. Two different computers
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The advantage of Configuration 1 was that we were familiar with the hardware and software interface and new approximately the level of complexity involved to achieve the integration and what we needed to do to use and maintain the system. The downside was that we were unhappy with the functions of the available (as of 2001) B&G hardware and we did not like our experience interfacing a second RADAR repeater to the Furuno RADAR.
The advantage of Configuration 2 was that we could achieve a reduction in the complexity of the wiring by about 50%. Also, SeaTalk was faster then NMEA but our desire to include the Northstar defeated some of the inherent savings in complexity because we would have to provide a NMEA interface. The downside, based upon our evaluation at that time, is that we felt that the Raytheon Navigator product was not as easy to use as VNS from Nobeltec.
Wiring Diagrams for the 2 Configurations
(Click on Image for Enlargement)
* Note: We finally chose the implementation on the right which uses Nobeltec's VNS rather than Raytheon's Navigator software. However, we modified the original approach by eliminating B&G and Furuno hardware and we went with all Raytheon. (I think it didn't really matter much, but now that the system is working, the only "issue" we can see, is the NMEA Vs SeaTalk priority scheme. We have worked our way around this issue very nicely but it is an issue that we would not have had to face if we had stayed with the B&G and Furuno hardware and worked completely in NMEA mode. In the end, everything works fine and appears to be reliable so the configuration we chose is a viable solution.) We believe that the implementation on the left is the better technical and more elegant solution but we went with the other configuration because, as we said earlier, we did not feel the Raytheon Navigator software product was a s robust as Nobeltec's VNS product (Decision made as of 1/2001.). Using the configuration on the left, you must use Raytheon products. However, either Raytheon or Nobeltec can be used with the solution on the right. Moving away from a pure SeaTalk environment, complicated the wiring but we liked the idea of building our system to have flexibility to address products other than Raytheon SeaTalk.
At the heart of the electronics integration is the GAC (GPS - AUTOPILOT - Computer) Controller pictured below:
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The KISS GAC (Keep It Simple Stupid GPS, Autopilot & Computer ) Controller is composed of 3 rotary switches that supports "mindless" operation of the equipment. The rotary switches control:
Which GPS unit is usedWhich Autopilot system is used
Which input from one of the 2 GPS's or 2 Computers is used to control the Autopilot's Waypoint/XTE
The user does not have to worry about making connections to various instruments / computers and all is failsafe in that any combination is allowable without harming the system.
The GAC allows us to choose amongst 16 different configurations of GPS, computer and controller functions. (Note: By controller we mean what signals, GPS 1, GPS 2, Computer 1 or Computer 2 will control the Autopilot.)
Equipment Interfaced through GAC
 PTC II Radio ModemSeaTalk to NMEA Converter
GPS (Northstar 951)
GPS (Raytheon WAAS 951)
Autopilot Interface for Pilot (6000+)
Autopilot Interface for Pilot (7000+)
IMARSAT-C
2 Meter Packet Radio
VHF DSC Radio
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Behind the scenes:
The wiring for the system is not all that complicated. The biggest area of confusion is making sure that the NMEA signals and the SeaTalk signals are properly interfaced and that the priority scheme for SeaTalk over NMEA is addressed. Since it was desired to drive the autopilot using other sources than SeaTalk (Raytheon WAAS 300 and Raytheon Wind/Speed/Depth/RADAR and repeater modules), namely a Northstar 951 GPS, and Nobeltec's VNS running off of 2 computers (laptop and desktop for backup), the MEA/SeaTalk priority scheme required that the SeaTalk output from the WAAS 300 had to be fed to the system via NMEA. With this in mind, the option was preserved to bypass the NMEA input from the WAAS and go directly from the WAAS to the AP via SeaTalk. To do this requires that the SeaTalk cable be plugged into WAAS on startup and that a way point be established on the 300. Otherwise, the SeaTalk cable is not required. However, if full information display is desired on the SeaTalk repeaters, you are required to make sure that the proper NMEA sentences are presented to the network via the Autopilot Selector switch described below. It was also found that the system can be brought up with the SeaTalk cable attacked as long as the WAAS 300 was not selected as the AP Controller. The only advantage that this provides is that all the GPS information can be displayed on the ST 60s Multis and the ST-80s.
Serial Ports:
5 computer ports are utilized on the laptop and 10 are utilized on the desktop. The GAC interface for both computers uses Ports 5 through 8. Since much of the functionality between the machines is redundant, using the same ports and pin outs simplified the overall design and minimizes debugging and maintenance. The wiring diagrams for the connection supporting the interface between the following equipment can be seen in the attached diagrams:
Detail documentation for both computer interfaces
Additional Documentation
Rotary switches are used to control how signals are fed through the
system. The guts of the rotary switches can be seen by dropping down
the Nav station panel. 3 large polished stainless steel hinges are used to support the panels.
GPS Control
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AP Central
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AP Selector
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Complexity of operation is minimized at the cost of adding a few more wires. The beauty of the approach is that there are no exposed wires at the Nav Station: There are a total of 16 different combinations of equipment configurations that can be chosen using these 3 switches.
GPS Selector Switch
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Autopilot Controller Switch
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Autopilot Selector Switch
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Navigation Equipment to Computer interface & Computer to Stereo System Interface.
Shown is the Interface circuitry for the Desktop
(The laptop looks similar)
The item in the middle is the bus bar interface between the
Computers 2 standard serial I/O ports and the 8 port serial
I/O port expander card (Equinox) on the Desktop and the various interfaced equipment
This setup is reproduced for the laptop computer with the condition that we are limited to 5 serial I/O ports.
We purchased the serial I/O ports from:
Additional Notes:
The great find here are the French made interconnects that we purchased from Ward Marine Electronics in Ft. Lauderdale. They are a little pricey but they make interfacing the equipment easy and neat. We highly recommend them.
In the lower right hand corner is the FM Converter to interface the output of the computer to the boat stereo system. With this device, we can conveniently listen to MP3 and digitized Music and DVD videos anywhere in the boat. This we purchased from Concord Marine Electronics in Ft. Lauderdale. I believe that most car and stereo stores also carry the FM Converters. The nice thing about the converter is that it greatly reduced the wiring complexity and the length of wire runs to interface to the stereo system.
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