Seatalk1 Advice

[SurlySailor]

Hi All,

I have a relatively new to me boat and I am trying to fix some of the hidden features we found while sailing last year. One the issues that has proven difficult to troubleshoot is a faulty boat speed indicator. The previous owner mentioned that he replaced the sensor three times but could never get it reliably working. Which has led me down a rabbit hole trying to figure out how Seatalk1 and the ST 60 system works.

Current system is all ST60 displays, ST6000 Autohelm, and a RL 70c at the Mac station and RayNav 300 in the cockpit along with displays. I also a Raymarine Seatalk1 / NMEA 0183 interface box connected to the RL70C that ties into a VesperMarine XB8000 AIS wifi.

I traced the airmar sensor wire until I found it disappearing into a non removable headliner below the instruments. I have found a two previous splices on that wire and suspect there is some chafing or incorrect splicing leading to the issue. The sensor it self is a ST800 and i have followed the troubleshooting steps to confirm that the paddle wheel sensor is still delivering temp data and I cleaned the paddle wheel very well to no avail.

I think i need to buy a new sensor, the question I have is can I tie the new sensor in at the interface box and have it still talk out on the SeaTalk Bus to all the instruments on it or is SeaTalk1 Unidirectional in that the Airmar sensor needs to be plugged into a specific instrument.

Any other advice or Seatalk1 for dummies reading material would be greatly appreciated

Thanks

[Tillsbury]

The sensor has to be wired directly to a speed instrument. The ST60 Speed has special connectors for it. However, you might have a Tridata (or Bidata) which can accept it. The ST60 Tridata has connectors for both depth and speed instruments, as well as the Seatalk interfaces. You can connect your transducer to the Tridata, and then set the Tridata to be the "Master" (i.e. to receive and interpret the speed information), and your ST60 Speed display to be "Slave" (i.e. to listen for speed information on the SeaTalk bus and just display it). I did exactly this when I swapped the positions of my Tridata and Depth displays.

Another option is to get a long flexible poking stick and see whether you can push it down the opening and find the other end of it somewhere

[SurlySailor]

Thanks for the info. Do you know if you are able to remove the instruments from the faceplate or do I need to get behind them? Getting behind them requires taking off a pretty large and well secured shroud up on deck.

[Tillsbury]

No, they come off pretty easily. The grey cover flicks off by putting a blade underneath and tweaking outwards. Be super careful not to break or force them off. Then under the rubber keys there are four screws holding it to the bulkhead. Get everything working before you screw it all down again.

[pcmm]

Originally Posted by Tillsbury

No, they come off pretty easily. The grey cover flicks off by putting a blade underneath and tweaking outwards. Be super careful not to break or force them off. Then under the rubber keys there are four screws holding it to the bulkhead. Get everything working before you screw it all down again.

That will break the instruments. The head units are secured with 2 small threaded brass rods with thumb nuts for each. You have to have access to the back of the instruments to remove them

[Jeanneau 45.2]

DITTO THE REQUIREMENT FOR REAR ACCESS. SAME UNITS THAT I HAVE AND I HAVE HAD TO REMOVE THEM, REQUIRING ACCESS TO THE TWO KNURLED NUTS BEHIND THE BULKHEAD.

[Tillsbury]

Originally Posted by pcmm

That will break the instruments. The head units are secured with 2 small threaded brass rods with thumb nuts for each. You have to have access to the back of the instruments to remove them

Depends on the type of installation. That's how you do it with good access behind. In a hidden access situation such as a bulkhead where you can't get access they can be installed from the front.