GpsMap 276C VHF/DSC Setup
 

Now, that the problem with the NMEA interface of GpsMap 276C with my
autopilot is practically solved with the 3.21 upgrade, I would like
to rise again the issue about the DSC, making the following questions,
which I tried to made to Garmin, but has not received a consistent
answer:

a) As I already have the Map276C sending NMEA messages to the autopilot
and to the PC chart plotter software, and I am receiving NMEA messages
from the depth sounder, all this working fine using the Map276C COM1 at
4800 bps, would be possible to make a interface with a VHF/DSC radio
in order to use the new DSC function of Map276C?
b) Knowing that the gps allows sending NMEA messages up to 3 devices,
and I am using only 2, can I use the COM1 to send NMEA to my VHF/DSC?
c) But, as I am receiving NMEA from the depth sounder, could I mix
this info with the NMEA from my VHF radio in the COM1 to receive the
"Position Reports", assuming that my new radio has NMEA in/out?
d) If the answer is NOT, than I ask: can I use the second serial port
COM2 of GpsMap276C to make this connection?
e) But how I can do this, if the GpsMap276C does not allow me to set
BOTH serial ports to NMEA?
f) And, If I could use the 2 serial ports set to NMEA, how I can setup
the COM2 to 9600 bps, which is the speed that DSC needs, if the actual
software of GpsMap276C does not allows me to make this change?
g) Concluding: has anybody successful tested the DSC function of
GpsMap276C, including the reception of "Position Reports"?
h) If yes, could he please, explain to me how this is done?

Thanks

Pascal

On 30 May 2005 21:44:12 -0700, "Pascal" wrote:

Now, that the problem with the NMEA interface of GpsMap 276C with my
autopilot is practically solved with the 3.21 upgrade, I would like
to rise again the issue about the DSC, making the following questions,
which I tried to made to Garmin, but has not received a consistent
answer:

snip
b) Knowing that the gps allows sending NMEA messages up to 3 devices,
and I am using only 2, can I use the COM1 to send NMEA to my VHF/DSC?

An NMEA "talker" should be able to drive at least 4 "listeners"

c) But, as I am receiving NMEA from the depth sounder, could I mix
this info with the NMEA from my VHF radio in the COM1 to receive the
"Position Reports", assuming that my new radio has NMEA in/out?

You can not simply "mix" the outputs of two NMEA talkers - you need to
use an NMEA multiplexer to combine them.


f) And, If I could use the 2 serial ports set to NMEA, how I can setup
the COM2 to 9600 bps, which is the speed that DSC needs, if the actual
software of GpsMap276C does not allows me to make this change?

Are you sure the DSC data from the radio is sent at 9600? NMEA-0183
should all be 4800.






--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

Thanks Peter,

I really do not know if DSC is 9600 or 4800. By the way, as You are the
"pope" on NMEA, can You explain to us the format and meaning of the
DSC/DSCE and the AIVDM messages?

Thanks again


Pascal

c) But, as I am receiving NMEA from the depth sounder, could I mix
this info with the NMEA from my VHF radio in the COM1 to receive the
"Position Reports", assuming that my new radio has NMEA in/out?

You can not simply "mix" the outputs of two NMEA talkers - you need to
use an NMEA multiplexer to combine them.

how much do these things cost? I found one once and it was about USD
500 :(

Web@shaw,
GO TO PETER'S SITE!!
http://vancouver-webpages.com/peter/
find:# NMEA Data Capture and Display Programs, Hardware, etc.
in there you will find:
"NMEA Hardware
(Mulitplexers, protocol converters, filters, etc. are listed below)"
= so scroll
That is why I appreciate what Peter has done for all of us....

Matt Colie
Lifelong Waterman, Licensed Mariner and Pathological Sailor



wrote:
c) But, as I am receiving NMEA from the depth sounder, could I mix
this info with the NMEA from my VHF radio in the COM1 to receive the
"Position Reports", assuming that my new radio has NMEA in/out?

You can not simply "mix" the outputs of two NMEA talkers - you need to
use an NMEA multiplexer to combine them.


how much do these things cost? I found one once and it was about USD
500 :(

On 31 May 2005 12:19:26 -0700, "Pascal" wrote:

Thanks Peter,

I really do not know if DSC is 9600 or 4800. By the way, as You are the
"pope" on NMEA, can You explain to us the format and meaning of the
DSC/DSCE and the AIVDM messages?

Sorry - I don't have any info on the DSC and DSE sentences. I have
manuals for two radios that should send those sentences, but they
don't give the sentence formats, and a short web search hasn't turned
up anything useful.

If you have a radio that does send those sentences, you should be able
to capture the data (with Windows Hyperterminal, or similar program).
Once you have captured a few sample sentences, it should be fairly
easy to determine the format. (See my NMEA FAQ for the formats of
other sentences...)


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Ok Peter,

I do not have a VHF/DSC radio yet, maybe somebody here has one and
could do this so that you can dissect the messages.

Thanks anyway and best regards

Pascal