GPS

Depends on the output type really - if your using something like seatalk/nmea2000/navbus then there really isn't a limit for you to be bothered about. However if you are using the NMEA0183 output (which is fairly standard) then in reality/theory you should be limited to 4 listeners from 1 talker which is what the NMEA specification states.

In practice you may get away with 1 or 2 more dependant on all sorts of factors - at work we regularly drive up to six listeners without the need for any buffer/amplifiers in the way, from a variety of GPS sets.
 
pau1gray said:
Depends on the output type really - if your using something like seatalk/nmea2000/navbus then there really isn't a limit for you to be bothered about. However if you are using the NMEA0183 output (which is fairly standard) then in reality/theory you should be limited to 4 listeners from 1 talker which is what the NMEA specification states.

In practice you may get away with 1 or 2 more dependant on all sorts of factors - at work we regularly drive up to six listeners without the need for any buffer/amplifiers in the way, from a variety of GPS sets.
Click to expand...


Would you just connect the output of the talker to the others without some form of special connection gizmo?
 
Generally you will get away with up to 4 devices, but it does depend on the device, some have such a low input resistance that one device can use up all the output capability.

You have to be careful as well because sometimes all seems to be working, but the data can be corrupted because a device fails to properly see the data, this is where the limit of the output is reached.

IMO If you need to driver more than three devices then use an NMEA buffer .
 
hightech said:
Generally you will get away with up to 4 devices, but it does depend on the device, some have such a low input resistance that one device can use up all the output capability.

You have to be careful as well because sometimes all seems to be working, but the data can be corrupted because a device fails to properly see the data, this is where the limit of the output is reached.

IMO If you need to driver more than three devices then use an NMEA buffer .
Click to expand...

Sorry but im a bit thick with this.What is and where can i get a 'Buffer'?
 
Tugw said:
Sorry but im a bit thick with this.What is and where can i get a 'Buffer'?
Click to expand...


Before you go away and spend a load of money!!!! All you need to do is connect the talker to the listeners with a bit of chocolate block / scotch block to check it works - then either go down the route of looking at buffers or connect them together in a better manner.

The main point where people tend to trip up is not just with the physical connections but the rates and fromats of the data that is being sent from the talker to the other instruments in which case you will need a different bit of kit called a multiplexer.

It will entirely depend on how old your equipment is, and also how well they have manufactured the kit / software to comply with the NMEA specification - it really can become a bit of a minefield to a non techy type of person. I'm not saying don't give it a go - you may be surprised when it all works with the cheap solution :-) If only you were closer to Plymouth I'd pop round and give you a hand.


An alternative to the actisense box may be somethign like this http://www.lindy.co.uk/rs-232-line-driver/32680.html at ~£30
 
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pau1gray said:
Before you go away and spend a load of money!!!! All you need to do is connect the talker to the listeners with a bit of chocolate block / scotch block to check it works - then either go down the route of looking at buffers or connect them together in a better manner.

The main point where people tend to trip up is not just with the physical connections but the rates and fromats of the data that is being sent from the talker to the other instruments in which case you will need a different bit of kit called a multiplexer.

It will entirely depend on how old your equipment is, and also how well they have manufactured the kit / software to comply with the NMEA specification - it really can become a bit of a minefield to a non techy type of person. I'm not saying don't give it a go - you may be surprised when it all works with the cheap solution :-) If only you were closer to Plymouth I'd pop round and give you a hand.


An alternative to the actisense box may be somethign like this http://www.lindy.co.uk/rs-232-line-driver/32680.html at ~£30
Click to expand...

Thanks for the info,Ill give it a whiz and see what happens.
 
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