AIS and Lowrance plotters

aluijten

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I have no experience with either of them, but I did have an issue with the same kind of connection. Maybe this is of some help to you.

The problem I faced that official the NMEA protocol is RS422 and not RS232. The difference between the both is not in the signal pattern but in the signal levels.
Officially RS422 is a current-loop interface and RS232 is positive and negative 12volts.
Some manufacturers claim NMEA ports on their devices but actually implement RS232 interfaces. Also quite a few dialects of both interfaces are around. Sometimes it works, sometime it doesn't
In my situation the AIS produced positive 12 volts as a logical state (say a logical '1') and minus 12 volts as the other logical state).
This means however that when you measure this the polarity on the output wires changes relative to each other. This is also the reason why signal ground is not always the same as power supply ground.
My plotter do not enjoy this as it expected resp. 12 and 0 volts as the logical states.
I managed to solve this by putting in some electronic components.
You could go to a electronics store and buy a suitable device to convert between the two dialects of your devices.
 

hubert

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If it's a signal level problem with the nasa engine then you just connect a 4k7 resistor between the engine output and supply positive.
 

Gelfi

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Lowrance plotter do not have the necessary software to run AIS. The British agents said at the LBS in January that Lowerance were looking into a software update but it appears not to be available at this time.

I have emailed Lowrance main office but they don't reply so everything is still up in the air
 

jackho

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A general questtion to all. Does this apply to NASA only and all of the new lowrance models? Also can AIS be connected to the Ethernet port as AIS is available on the Lowrance radar input?
 

Phoenix of Hamble

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Only a plotter that supports AIS can receive AIS input from any equipment, beit NASA or another, and as far as I know, Lowrance doesn't support AIS.

The input on the plotter will be a function of what the AIS receiver generates.... ie, if it generates AIS data on NMEA0183, then you need to use the NMEA input on the plotter..... I might be wrong, but I think the Ethernet port is used for NMEA2000, and as such would need an AIS receiver that generated an NMEA2000 output, but even then, the Lowrance would ignore AIS input as it isn't programmed to know what to do with it.
 

Dazedkipper

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Thanks for your thoughts guys. It is as I suspected, will have to wait and hope that Lowrance get themselves sorted and brought up to date!
 
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