T&T: Interfacing autopilot and chartplotter

[Peter Bennett]

Check what sentences your autopilot wants.  The BWC and BWR sentences only have bearing to waypoint, and the pilot will probably also want cross-track error, as given in the XTE sentence.  What other sentences (if any) are the two systems sending to the pilot?

The RMB sentence includes both bearing to waypoint and XTE, and seems to include all the data my Raymarine pilot wants.  

APB is an older sentence (use discouraged on new systems) that has both bearing and XTE.

Thursday, August 31, 2006, 6:17:39 AM, Lewis wrote:

LB> I am unable to get my navico auto pilot PH 8000 to respond to commands
LB> issued from a R70RC Raymarine chart plotter. The auto pilot
LB> understands the commands from a navigation program on a laptop e.g.
LB> $ECBWC,183107,4420.66,N,07600.81,W,130.81,T,144.65,M,0.971,N,002*32
LB> $ECBWR,183107,4420.66,N,07600.81,W,130.81,T,144.65,M,0.971,N,002*23

LB> A sample from the chart plotter using hyper terminal

LB> $ECBWC,211611,4421.01,N,07600.90,W,112.5,T,126.0,M,0.72,N,GOTO CURSOR,D*68
LB>  $ECBWR,211611,4421.01,N,07600.90,W,112.5,T,126.0,M,0.72,N,GOTO CURSOR,D*79

>>From what I can see the sentence structures are identical, Why does it
LB> understand NMEA data from a laptop and not similar data from the chart
LB> plotter? Could there be different line feed or carriage return
LB> characters, maybe different voltages? Could feeding the data through a
LB> multiplexer solve the problem. I have tried everything I can thing of
LB> with no success, Does anyone have any suggestions.

LB> Thanks






-- 
Peter Bennett, VE7CEI    Vancouver, B.C., Canada
Lien Hwa 28 (AKA Polaris 30) "Sea Spray"
GPS and NMEA info: http://vancouver-webpages.com/peter 
Vancouver Power Squadron: http://vancouver.powersquadron.ca