Help with nmea 0183 interface of units with standard horizon plotter

[petrolhead63]

Hi, this is all new to me! I am good with wiring so once I know what is what it is fine. I have 5 instruments to link together and understand a unit can talk to three and listen to one. However I think I may be missing something.

I have a Standard horizon plotter, then 4 other units. DSC VHF, AIS, Auto pilot and a GPS repeater. The auto pilot is old autohelm but I have found the connecter for nmea and have a cable.

My plotter has three output wires and two input ones....the out put ones it displays as one for auto pilot, one for vhf and other for other listeners. That does three of my units leaving one.

What I am unsure of is if each output wire could talk to three listeners or is this plotter just using three separate wires instead of one to deal with a total maximum of three listeners.

Help very much appreciated from anybody brighter than me with this!

 

[pvb]

You say you have AIS, this is presumably a receiver, so needs to be connected to the input of one of the ports. Also, the baud rate of that port needs to be changed to 38400, which will then disable the output of that port. Which leaves you with two outputs, each of which can drive more than one listener.

 

[PaulRainbow]

An input port is a listener, it can only receive data from a single source.

An output port can send data to 3-5 devices.

Frinstance, a GPS receiver can send GPS data to your plotter and VHF. The plotter could receive the GPS data on an input port, but nothing else on that port.

You'll need to post exact makes and models of equipment for more detailed advice.

 

[petrolhead63]

Hi, thanks for such quick responses. The gear is nothing fancy....all new old stock collected over a period to upgrade the ancinet stuff on our Storebro cruiser.
Standard Horizon CP150 GPS/plotter with its own antenna fitted on radar arch.
NASA repeater
NASA AIS
Autohelm ST6000 auto pilot
Cant recall the new DSC VHF..however it has in and out nmea, I will get the model later.
Thanks

 

[PaulRainbow]

Hi, thanks for such quick responses. The gear is nothing fancy....all new old stock collected over a period to upgrade the ancinet stuff on our Storebro cruiser.
Standard Horizon CP150 GPS/plotter with its own antenna fitted on radar arch.
NASA repeater
NASA AIS
Autohelm ST6000 auto pilot
Cant recall the new DSC VHF..however it has in and out nmea, I will get the model later.
Thanks

Plotter :

NMEA In 1 - VHF
NMEA Out 1 - VHF, NASA repeater

NMEA In 2 - AIS (set to 3800)
NMEA Out 2 - Unused

NMEA Out 3 - Autopilot

 

[petrolhead63]

hi, thanks so much. I have routed most of my cables and you have it seems told me how to connect it all up. Would I right in saying that port connected to the VHF and NASA repeater could talk to one more listener? if I ever had anything.
The baud rate is not mentioned in the AIS handbook it just says connect nmea and how but I can look into that.

 

[pvb]

hi, thanks so much. I have routed most of my cables and you have it seems told me how to connect it all up. Would I right in saying that port connected to the VHF and NASA repeater could talk to one more listener? if I ever had anything.
The baud rate is not mentioned in the AIS handbook it just says connect nmea and how but I can look into that.

Now that you've told us that you have a CP150 plotter, this changes the advice we've given. Your plotter apparently can't display AIS data, and can't be set to the 38400 baud rate required. All the other connections should work fine.

 

[petrolhead63]

ok, likewise reading the basic NASA AIS booklet it only has one nmea connection which is to the output from gps. So I assume the AIS does not send info to the plotter it merely receives position information.
The AIS could then use the unused out 2 on the plotter?

 

[PaulRainbow]

ok, likewise reading the basic NASA AIS booklet it only has one nmea connection which is to the output from gps. So I assume the AIS does not send info to the plotter it merely receives position information.
The AIS could then use the unused out 2 on the plotter?

I assume your AIS is the NASA AIS "radar" with it's own display ? If it needs GPS you can use NMEA 2 out or NMEA 1 out.

 

[petrolhead63]

yes it is the little NASA unit with own display and yes it takes gps info to display the boat position on the display. I assume the unit would work fine as AIS "radar" without the gps signal but not show the vessels own position as co-ordinates but simply centre of screen. Am I correct in thinking I can connect three listening nmea devices to a single transmit wire from the plotter?

None of this equipment is very fancy by modern standards but will be nice to have. Our last cruiser, also a Storebro (31 Baltic) had nothing but a monochrome plotter and depth/log and that did us just fine for 16 years I never worked out how to connect the very old extremley heavy duty NECO auto pilot to the gps although I was told if I found the right man it could be done using the NECO chain/motor etc giving the best of both worlds. Quality mechanical parts from a bygone age that are robust with modern electrical control!

This "new" boat to us we have had just over 2 years and have been working through it. It still had its DECCA system insitu! hence the upgrading to at least gear from this millenium.

The biggest pain I have is I kept our older Navman plotter which has an age worth of waypoints on it but I can't transfer these to the new standard horizon plotter. It is going to be a long task manually inputting them unless anybody knows a better way!

I kind of wish I had just put the old plotter on the boat...it currently is used running of the 12 fag lighter socket with the aerial wedged in a cup holder in the saloon I actually think other than being black and white its just as good as the standard horizon with a slightly larger screen too.

 

[pvb]

yes it is the little NASA unit with own display and yes it takes gps info to display the boat position on the display. I assume the unit would work fine as AIS "radar" without the gps signal but not show the vessels own position as co-ordinates but simply centre of screen.

I think you'll find it won't work properly without a GPS input.

Am I correct in thinking I can connect three listening nmea devices to a single transmit wire from the plotter?

Yes.

 

[MikeCC]

The biggest pain I have is I kept our older Navman plotter which has an age worth of waypoints on it but I can't transfer these to the new standard horizon plotter. It is going to be a long task manually inputting them unless anybody knows a better way.

Yes, can be done using a PC and downloading them and then uploading to new unit. Will probably need some GPS waypoint manager software; no doubt there's something free available. Perhaps also a barewire serial/USB cable if PC doesn't have serial port. Might be best done in comfort of home. And test with a couple of waypoints first to ensure they show OK on new one.

 

[Danny]

I assume the unit would work fine as AIS "radar" without the gps signal but not show the vessels own position as co-ordinates but simply centre of screen.

It won't work without GPS data. It'll know where all the other craft are but will have no idea where you boat is!

 

[petrolhead63]

It won't work without GPS data. It'll know where all the other craft are but will have no idea where you boat is!

haha! I better get it right then.

 

[petrolhead63]

Yes, can be done using a PC and downloading them and then uploading to new unit. Will probably need some GPS waypoint manager software; no doubt there's something free available. Perhaps also a barewire serial/USB cable if PC doesn't have serial port. Might be best done in comfort of home. And test with a couple of waypoints first to ensure they show OK on new one.

hmm, sounds a bit beyond me...not too good with IT, but I will look into it. I think the navman is not naturally able to connect to a pc. That said I have most of the the same waypoints also on an old handheld magellan gps315 which I think can connect to a pc? perhpaps thats easier.

 

[snowbird30ds]

You may need to use something to convert the output from the old gps to match the format of the new plotter, gpx will be likely acceptable to the new plotter for a batch of waypoints, a program called gpsbabel is good for converting formats, Memorymap can also import and export in lots of formats.
Yes nasa ais radar does need gps input (I had one on my last boat) and it has no output.

 

[petrolhead63]

Hi, I am surfacing again now work is nearing completion. I have routed cables, cut holes and fixed instruments in place ready for wiring up finally and getting the nmea right.
I think I have worked out how the four units all connect back to the gps plotter but have one query...which may seem daft.
The plotter actually has a common/ground/reference wire on the loom.
The four surrounding units have two methods to connect nmea ground/reference, two have cables to connect to the the cable on the gps plotter..easy enough.
Two rely upon internal unit connection to the boats ground/negative with the instructions to ground the plotter wire to boat ground. So should I connect the plotter nmea ground wire to boat ground as well as the two instruments or should I connect these two instruments to ground too ...ie all 5 connect nmea to boat ground circuit.

 

[PaulRainbow]

I doubt you have a ground plane, so forget it and connect anything marked thus to 12v neg.

 

[petrolhead63]

Hi, apologies..what do you mean by ground plane? I was referring to the 12V negative as my ground. By the way its a Storebro and is fully bonded throughout with metal strap bonded in the grp acting as conduits...not that I planned using this for nmea.

Are you saying connect the plotter nmea reference/ground wire to 12V negative and then all four other instruments to the same?....using the 12V neg to link them all together.

I think the VHF MT500 has also a + nmea wire to go to ground according to instructions i have found.

Thank you for the guidance...its all new to me nmea interfacing.

 

[snowbird30ds]

Mine has nmea grounds connected through 12v neg and all works fine.