Plotter Heading Says "Magnetic", but Variation Applied Incor

[Loy]

On the Nav Data Screen I have HEADING displayed. It says the value is MAGNETIC. But the value displayed is exactly the local VARIATION applied to the actual magnetic value inputed whereas the variation should be applied to magnetic to obtain true.
For example:
Input value is 077 deg magnetic. The variation is 7 deg W. This means the TRUE heading should be 070 deg, but the display says 084 deg! It is as if the TZT2 thinks the input is TRUE, when it actually is magnetic.
The Radar display is set to TRUE and the heading line intersects the bearing circle at 077 deg -- again indicating the device believes the input is TRUE. Because the input is actually magnetic, the intersection should be at 070deg.
I have other devices on the NMEA2000 network that display magnetic correctly.
The TXT2 has Initial Setup settings for NMEA2000 and NMEA0183, but only the OUTPUT portions.

Where can I find the setting to correct this and have the TZT2 determine the difference between magnetic and true inputs?

 

[Johnny Electron]

You want to make sure you are running current software in the MFD. You will want to check what Heading source is selected in the SENSOR LIST along with what source you have selected for Mag Var. As far as changing your heading from True to Mag and vice versa that is under "UNITS" in the SETTINGS menu.

 

[Loy]

Thanks for the quick comeback, Johnny.
I'm running software version 5.03; look forward to the update releasing next week.

My SETTINGS -UNITS-BEARING DISPLAY is set to MAGNETIC.

In my DATA SOURCE Settings:
Mag Variation can be set to either of the two listed sources [TZT2 Salon or NEMO Gateway]. Neither setting has any effect.
HEADING is set to the only listed source [NEMO Gateway].

Irrespective of the possible source changes available, the DATA SOURCE page values are Mag Variation values = W8.0 deg [correct], and HEADING values = 077 deg M and 069 deg T [this also correct for the being inport at the time.
At the same time, the Data Display shows heading 085 deg MAGNETIC.
Two illustrative photos attached.

 

[Johnny Electron]

You should open a case with tech support so they can collect data from your system. We haven't seen any of the Furuno sources or any of the major players equipment have this issue with Mag Var using current software. If you have other GPS,Heading, and Mag var sources you might try different combinations to see if you can get a different result. I suspect that there is some + or - missing from the PGN data being used. You could also try a factory clear of the display just in case it is some strange software glitch.

 

[Loy]

Johnny,
I'd prefer not to do a display reset until after seeing what the upcoming software update will do. There are a MULTITUDE of owner-settings I'd hate to have to do over from scratch.

Notwithstanding that, here's a copy of the exact NMEA 0183 heading sentence coming from the Robertson Rate Compass RFC35R via AP Controller J300X into the RosePoint NEMO Translator that then goes to the TZT2 via NMEA2K:
$APHDG,075.9,M,,,0.008.0,W*43

The NEMO is then sending PGN 127250 at 10HZ. I don't know how to break into the PGN to see its exact message.

So..... Is the HDG sentence above OK, or is it somehow structured incorrectly? After all, the autopilot is 20 years old and NMEA 0183 standards have changed.

Mike

 

[Loy]

My apologies to all. The problem with the digital heading display was entirely my faulty 'knobology.'
Some months ago I had set the heading correction value in Installation Settings to correct the radar display heading line intersection on the bearing circle to confirm with the magnetic head [given my location's variation].
1. I now understand that NU display on the radar is in TRUE. This makes sense because an overlay on the chart would always confirm to the chart in NU.
2. My 'correction' did show the radar head intersecting the bearing circle in magnetic, but it was not a correct representation. The result was a completely erroneous digital heading display.
Sorry,
Mike

ps: Looking forward to the software update this week.

 

[Johnny Electron]

Glad you figured out the heading.
In relation to the next software release, please see the following post.
viewtopic.php?f=28&t=5039#p20516