Lowrance GPS & XM DSC Not talking!

[wetandwindy]

I've trawled the archives, but can't see a solution to this, so would appreciate any guidance. I've got a Lowrance M52i s/GPS linked up to an XM DSC VHF. The DSC resolutely refuses to acknowledge the presence of the GPS. All cables are sound and connections OK. I've tried all the permutations of the NMEA speed that I can see and also tried every other setting possible. What am I missing here guys? /forums/images/graemlins/confused.gif

 

[Danny]

Paul, apologies if this is too obvious but is this a new DSC? If so, have you entered the MMSI because I don't think it'll display the position until that's done.

 

[wetandwindy]

Yep, MMSI correctly entered! DSC works well, but the Bl@*dy thing won't accept the GPS input!

 

[Danny]

This one's a bit obvious as well... when you set the baud rate on the M52i did you make sure the NMEA enabled checkbox was ticked?

 

[pvb]

Just a thought...

The data cable which comes with the M52i has a diode and resistor built in to it. These aren't needed for some radios. Is it possible that the XM is one such radio? See manual supplement for details.

 

[wetandwindy]

Danny, cheers, I had to play around with the menu quite a bit originally, but yes it is. /forums/images/graemlins/frown.gif

PVB, I looked at that and have connected the cables prior to the resistor/diode, to no avail! I will now try completely disconnecting the diodes and see what that does. I assume that it won't cause any damage.... ? /forums/images/graemlins/crazy.gif

 

[KREW2]

A shot in the dark, is it earthed

 

[wetandwindy]

Earthed in what way? All cables were connected as per installation instructions.

 

[duncan]

there can be some confusion about earthing - as happens a lot with NMEA devices from posts here!

gererally connecting GPS with VHF........

any shield, earths or NMEA -ve 's should be directly connected between the 2 devices rather than relying on them connecting somewhere on the boat through both being connected to earth.

other than that it's NMEA +ves together, which you have done.

GPS as NMEA out in software for the com port if it has to be configured

NMEA out message set to one acceptable to VHF - probably 2.0 for these units

VHF set to accept same message

baud rates same 4800/9600

and for some MMSI number programmed into VHF or it won't show position

also for some set VHF software to update position automatically from NMEA input (rather than manual input)


may have missed a step but I am sure someone will point it out