NASA Electromagnetic Log

nickcole

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Hi - Last winter I installed the NASA Electromagnetic Log transducer and connected it to the Raymarine ST60+ display. NASA state that their transducer will work with any compatible NMEA 0183 display but it's not working. The display shows " - - - - ". The NASA controller NMEA light flashes, indicating that the signal output is okay. Am I missing a trick here?
 

dolabriform

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Hi - Last winter I installed the NASA Electromagnetic Log transducer and connected it to the Raymarine ST60+ display. NASA state that their transducer will work with any compatible NMEA 0183 display but it's not working. The display shows " - - - - ". The NASA controller NMEA light flashes, indicating that the signal output is okay. Am I missing a trick here?

Which ST60+ Display do you have?
 

nickcole

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Not known - perhaps someone can advise..?
The Nasa transducer outputs NMEA0183 sentences VHW and VLW. What sentences does the ST60+ require?
[/QUOTE]
 

nickcole

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Good questions. I naively thought I could just swap the old paddlewheel transducer for the electromagnetic one - based on my understanding that the NASA control box provided the necessary compatible output. For clarification I have a Raymarine SeaTalk ST60+ network of instruments.
I'll be on the boat in a few days so I can make further investigations regarding the current set-up. Anything else I should check?
 

pvb

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Good questions. I naively thought I could just swap the old paddlewheel transducer for the electromagnetic one - based on my understanding that the NASA control box provided the necessary compatible output. For clarification I have a Raymarine SeaTalk ST60+ network of instruments.
I'll be on the boat in a few days so I can make further investigations regarding the current set-up. Anything else I should check?

I don't think you'll get it to work without a lot of messing about. Your easiest/cheapest solution would be to buy the matching Nasa display head for £85.
 

earlybird

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There might be a further complication. The Tridata needs the paddlewheel transducer connected to it, otherwise it acts as a repeater for Seatalk. This will be OK for speed etc. if you connect a NMEA converter but you might lose your existing depth data since the display won't be able to act simultaneously as master for depth and repeater for log/speed.
Take PVB's advice.
 

cpedw

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There might be a further complication. The Tridata needs the paddlewheel transducer connected to it, otherwise it acts as a repeater for Seatalk. This will be OK for speed etc. if you connect a NMEA converter but you might lose your existing depth data since the display won't be able to act simultaneously as master for depth and repeater for log/speed.
Take PVB's advice.
I think the Tridata allows depth and speed master/repeater to be set independently. But without NMEA to Seatalk it's no help.
 

duncan99210

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The OP has a network of ST 60 instruments, presumably linked by Seatalk. All he needs is to find one of the instruments with a vacant set of NMEA IN terminals, link the transducer output to that and that should work. IIRC there are a number of the ST60 series that have a set of NMEA IN terminals, anyone of them should do, including the autopilot computer/control head.
 

earlybird

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The OP has a network of ST 60 instruments, presumably linked by Seatalk. All he needs is to find one of the instruments with a vacant set of NMEA IN terminals, link the transducer output to that and that should work. IIRC there are a number of the ST60 series that have a set of NMEA IN terminals, anyone of them should do, including the autopilot computer/control head.
Not necessarily. For instance, my ST60 Graphic, which is a fairly general purpose repeater, does not recognise the NASA NMEA VHW and VLW according to the manual that I have.
 

dolabriform

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Looks like the Smart Pilot will accept the VHW sentence, but not the VLW sentence.

Two options I can think of,
1) Raymarine E85001
2) The ST60+ Multi display that I have sitting around and might be looking to sell. This will convert NMEA to Seatalk but I can't remember off the top of my head if it supports the needed ones
 
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