NMEA/Seatalk data conflict

[robbieg]

I am changing my pathfinder radar/chartplotter display to a C70 unit.

The C70 will be plugged into the seatalk bus from the raymarine autopilot-this will give it GPS data but also heading data.

The C70 NMEA input port will get data via a mulitplexer from a smart heading sensor and AIS. Anyone know whether I will end up with a conflict between the heading data coming in from the seatalk bus and the heading data from smart heading sensor via NMEA? If so anyway of turning of the seatalk heading data-I want the smart sensor data to prevail.

TIA

 

[alan17]

If I have understood correctly you will need to turn off the NMEA bridge in the C70 menu.

 

[pvb]

[ QUOTE ]
If I have understood correctly you will need to turn off the NMEA bridge in the C70 menu.

[/ QUOTE ]You have to turn NMEA bridging off to get MARPA to work anyway. But the NMEA bridging just outputs NMEA heading data on the SeaTalk bus - if there's already heading data there, this won't help, will it?

 

[pvb]

You haven't said which autopilot you have, but why not connect the Gyroplus unit to the autopilot and then use the NMEA fast heading from the autopilot to feed the C70. That way, all the heading info should be the same.

 

[robbieg]

Its an ST4000+. Problem is the Smartsensor unit connects to the autopilot by seatalk. In any event the nmea in port on the autopilot are already receiving gps and wind data.

Looks like one answer may be to put the GPS data through the MUX with the smart heading data and ais data and unplug the seatalk into the C70. Not ideal but at least the MARP and radar overlay should be OK and the plotter will have position data. I have put the query into Raymarine and will report back if they have any solutions.

 

[pvb]

[ QUOTE ]
Looks like one answer may be to put the GPS data through the MUX with the smart heading data and ais data and unplug the seatalk into the C70.

[/ QUOTE ]You have to have SeaTalk connected to the C70 in order to calibrate the Smart Heading Sensor.

 

[robbieg]

Unless I am getting confused (quite possible) can't I calibrate the smart sensor with the autopilot-the manual seems to suggest this is possible.

 

[Gypsy]

I believe the C70 takes heading data from the NMEA input as a priority over SeaTalk (as does the Pathfinder series - mine is RC530+) to avoid this specific conflict. If there is no NMEA it uses Seatalk.

If you are using the Smart Heading Sensor to help your autopilot as well as improve MARPA you may find my notes about my installation HERE useful. I have a 6000+ Autopilot which may have a different computer than your 4000, but some of the issues may be the same.

Edit: I just looked at the SHS manual relating to installation with the 4000 AP. It requires the Fluxgate compass to go to the SHS so the issues I came across will probably not affect you but you might find it useful reading anyway.

 

[JayBee]

WOW! - this is way too techie for me, but I would like to be pointed in the direction of some reading material which might help me begin to understand this thread. Any suggestions?