If you haven’t read the previous posts in “What’s connected on Summer Dreams?”, here is Part 1, Part 2, and Part 3. In those posts, I outlined my installation of my radome, satdome, satellite radio, 3G router/wi-fi for Internet and voice line. Follow on that installation, I installed a cockpit TV and did all the wiring to support the components. In the case of the satdome, I had to wire the GPS to the ACU unit so that the satellite dish (in the dome) can quickly find the Bell satellite regardless where I’m at. This was the first introduction into boat networks. Of course, my GPS is a Raymarine Raystar 125+ which was directly connected to my Raymarine C70 chart plotter via SeaTalk.
What is SeaTalk? As it turns out it was something that I was very familiar with being old school in computers. It’s essentially a RS422 serial connection (which defines the physical things) with a text based protocol (akin to what was used to talk to modems of old). Of course, my Raymarine 33STV ACU required NMEA0183. What’s NMEA0183? Well, is like SeaTalk except it’s RS232 with a different protocol. Unfortunately, you can’t connect them together. To keep things short, I kept the SeaTalk GPS connection and discovered that my C70 had a NMEA0183 “output” port.
Wiring NMEA0183 is fairly basic, as so far as there are no special connectors or cables required. Standard station cable, i.e. 4 conductor “telephone” wire or Cat-3 wire, is all that is needed. Doing NMEA0183 does, however, require some attention. It is a serial connection where there can be only one device sending (talking) but can have more than one (though less than 3) devices receiving (or listening). That is the definition of RS232 and its point to point nature. SeaTalk, on the other hand, was designed by Raymarine to overcome this problem. As mentioned before, SeaTalk uses RS422 which is a “bus” type of connection. This means devices can talk and receive to each other across the cable. The downside is that SeaTalk is proprietary to Raymarine (meaning only Raymarine electronics use it) and it uses special cables and connectors, which are expensive.
In either case, I was able to complete my install without any problems. However, this was just the tip of the iceberg when I decided to network all my electronics together. That will be explained in up and coming posts.
So up to this point, by the end of the 2010 boating season everything I set out to do was complete. My first real trip in my boat occurred in 2010 and it provided me with invaluable experience as to what my next project will be; redoing my 12V fuse panel. Why? Well, with all the addition of a satdome, TVs, etc. is was very easy to drain my house battery and I did it on several occasions. I needed a finer control to be able to “turn off” some systems that I would never use while at anchor. Prior to this, only the main battery switch (or the device had a power switch) controlled things. Things like the VHF DSC radio (Raymarine Ray240) and the GPS (Raystar 125+) were always powered with the battery switch is on. This parasitic draw is what would drain my batteries.
It was the above issue that defined my project for the 2011 boating season. As it turned out, this was only one of my projects for the 2011 boating season. Rewiring the 12V systems was simple and cheap in comparison to the other projects. The other projects were dedicated to helping me navigate the locks, with physical control that is, and controlling the amount of fuel I burn. More on that in a later post.
For the 12V rewire, as you can see from above, all the bright red wires are new 12V power leads. What can’t be seen is the WeatherDeck switch panel (in a pic below) where the wires come from. Also, you can see the Raymarine junction box for the SeaTalk network. I had to rewire SeaTalk to allow the network to have its own power lead on the switch panel so that I can turn off the GPS/network, VHF/DSC, and the C70 separately to each other. Ignore the labels and the remote control on the right, those are hints to my other projects.