GPS NMEA 0183 Output to more than one Device

[pjf]

Hi,

Quick question; is it possible to supply GPS data from a single GPS receiver to 2 or more different instruments. i.e and AIS display and VHF radio?

If so, how best to do it practically?

Thanks

 

[LittleShip]

Short answer yes

There are special connectors for the job but if it's only a couple of appliances a chocolate block will do the job. You can probably find something waterproof that will make it look a little more professional.

Tom.

 

[David2452]

0183 is single talker multiple listener so yes it is normal within limitations, just use a junction box or even "Y" the leads. Don't try putting two inputs though unless the reciever is multi chanel 0183.

 

[Danbury]

Interesting thread... I tried adding a 3rd a few months ago, but it didn't work. I assumed it was because I had too many (it worked fine with any two). Is there no 'REN' type loading count like you get with telephone lines ?

 

[andyp]

Most reckon that one NMEA 'talker' can feed no more than four 'listener' devices.

Your difficulty adding a third device may relate to differing earth/return arrangements. Some are +ve and-ve while others work on signal and ground connections.

If you need to supply more devices then a multiplexer (costly) or one of Angus' YAPPs will be needed.

 

[pjf]

Thanks Gents,

Its kind of what I thought or rather, hoped.

Cheers

 

[David2452]

Just checked my NMEA 0400 standards manual and it states a maximum of three before a signal expander device is required, I had it in my head that it was more, I so rarely use 0183 nowadays that I had forgotten.

 

[ditchcrawler]

I feed four devices(Yeoman,VesperAIS,GPS repeater and Standard Horizon 2100 radio from my Garmin 128.Garmin said four should be OK especially as the feed to a repeater is very low.I also have a feed to my radar but that is not on very often but when it is on they all seem to work.

 

[bedouin]

Yes - many people connect multiple listeners to one talker with no issues but it is not guaranteed to work. You are in effect connecting the input circuits of all listeners in parallel and it is possible that that will cause interference between them.

Also it may make a difference (either way) if the devices are switched on or not

 

[David2452]

I feed four devices(Yeoman,VesperAIS,GPS repeater and Standard Horizon 2100 radio from my Garmin 128.Garmin said four should be OK especially as the feed to a repeater is very low.I also have a feed to my radar but that is not on very often but when it is on they all seem to work.

That is not unusual, the standards are what will work constantly and accurately, outside that may work but may not work all of the time and will also depend more on the quality of the install and shielding etc.