Hi everyone

I got a new B&G Hercules (v5.0.160) and a Lars Thrane A/S LT-500 AHRS compass.

I have discovered that B&G is incorrectly double-correcting the heading. The LT-500 sends a corrected heading in PGN 127250 (Field 2) and the deviation value used in Field 4. B&G software appears to be taking the already-corrected Field 2 and adding Field 4 again, resulting in an error equal to the deviation (up to 20° on my boat).

Proof: Expedition and A+T ATP1 on the same bus show the correct heading. The error only appears when the LT-500 internal calibration is 'Valid'. If the LT-500 is in non calibrated condition there are no deviation values communicated and the heading on the B&G system is correct.

Has anyone else seen Hercules v5.0 ignoring the NMEA 2000 standard for PGN 127250 Fields? I am considering moving to NMEA 0183 'Data Firewall' via the Hercules Serial ports to solve it, but this seems like a major Navico software regression."

Have you made a similar experience?

Thomas