B&G Chartplotter heading sensor error

[Qismat]

Hi,

I'm having an issue with my B&G Zeus 3 displaying information.

More often than not, the course heading shows as incorrect. maybe 4 or 5% of the time it will be correct and i think this is when there is actually current offsetting to make it look like its going straight. Often by 20-30 degrees. I have verified that the boat is heading in the direction of the course heading line, but on the chartplotter, the boats angle is off. It says we may be pointing 20 degrees further to starboard than we are. Its really annoying. It ends up showing that there is a 2-3 knot current pushing us in any direction at any point in time.

I'm wondering what I need to adjust in order to fix this. Is it the heading sensor throwing it off? A setting in the B&G? Is my electronic compass whack?

I've attached photos of what this looks like.





In these photos, we were actually heading 292 degrees, but the boat thought it was pointing at 318.

Any ideas?

[SVHarmonie]

When was the last time you calibrated you heading sensor? Are you sure somebody hasn't stored a chuck of steel near it?

[PFMcC]

Hello
I am having exactly the same issue. I have a Zeus3 plotter and a Precision 9 compass.
Did you get this resolved?
Thanks

[Pandor]

I don’t know the issue, but it can’t be a coincidence that the difference between 292 and 318 happens to be exactly the same as the variance that the plotter is showing.

[Gravitas41]

hi

Not sure if this is the same issue I had on taking delivery of my boat, but I found a setting in the BandG Zeus software to align boat heading and compass heading.



the precision 9 manual is the place to look...

assuming you have already completed a calibration (by driving the boat round in circles as part of the process) - then you can adjust the heading offset...

Heading offset
To adjust minor heading offset, select the Configure button (refer to page 2) to open the Device configuration dialog:
If required, enter offset in degrees.
Instance - the Instance is determined by the configuration process and should not require user adjustment.

there is a setting that adjusts the radar scanner to align too...

Adjust bearing alignment
This is to align the heading marker on the screen with the center line of the vessel. This will compensate for any slight misalignment of the scanner during installation. Any inaccuracy will be evident when using MARPA or chart overlay.
Point the boat to be perpendicular to the very end of a breakwater or peninsula. Adjust the bearing alignment setting, so that the heading marker and land mass intersect.

hope that helps...

[Dockhead]

Do you have the plotter set to substitute COG for HDG?


Does this happen only at very low speed?


Saw this very thing on a power boat recently which did not have the fluxgate connected with the plotter. If you're moving at a reasonable speed in waters without big currents, and provided you're not making leeway, then COG will coincide pretty closely with HDG. But once you stop, this will no longer be the case.

[Bycrick]

You can tell whether the problem is the compass itself or the display quite simply. Go to the Device menu on the MFD for the compass and click the Data button. That will display the data directly out of the compass. If that’s correct, the problem is MFD settings.

[PFMcC]

All the advice is appreciated, thank you!

The equipment on the boat is 2 Zeus3 MFDs (inside and out), a Hydra 5000 CPU, 214 MHU and external GPS antenna and 2 triton displays.

The boat icon has an erroneous heading consistently close to due North. The output data from the Precision compass is the direction of the boat’s true heading. So, not a compass error. This accurate compass heading displays numerically on both MFDs.

The data output from the external GPS antenna is COG.

As pointed out in the original post, the incorrect North heading (source?) and accurate COG are processed to calculate substantial erroneous ‘tide’ effects.

I have asked B&G Canada for help - and at present are uncertain as to cause.

Any further assistance would be appreciated.

Thanks
Peter

[PFMcC]

To answer earlier questions:
The heading error is at all speeds up to 7 knots.
The plotter is not set to use COG instead of magnetic heading, and does correctly identify the data source for the heading as the Precision compass.
Thanks

[kipwrite]

Resolved?

[PFMcC]

Unfortunately no.
B&G Canada in consult with their US counterparts are suggesting a reinstallation after backing up data. I hope to do this through the original installing company; they have access to Navico technicians directly.

[Jerry Woodward]

Originally Posted by Pandor

I don’t know the issue, but it can’t be a coincidence that the difference between 292 and 318 happens to be exactly the same as the variance that the plotter is showing.

I believe Pandor had it right. COG generally calculates TRUE north whereas a compass or your precision 9 heading sensor measures Magnetic north. In your case, the variation between true and magnetic is 16.2 degrees E. The Zeus can be set to display heading as magnetic or true. The True setting is "Auto" in which case it will add or subtract the variation for your location automatically. It is likely that your heading sensor settings are set to magnetic rather than true. So I would check to make sure your Precision 9 is set to Auto to give you a TRUE heading. If so, your True heading would be closer to 302 degrees in your example. Now the difference is only 10 degrees and this can be adjusted by turning the Precision 9 to point dead ahead, or programming an offset in the Zeus.

[Walltrip]

For some reason, all of a sudden, my Zeus 3 is not showing any magnetic heading or true wind angle data. Just dashes. I did not do the install and am having trouble getting information from the company that did. Is there an internal electronic compass in the MFD? Or would an external electronic compass have been installed? I have been skimming the manual with bo luck