[CA] [CA11] Autopilot heading and COG intermittent mismatch

[roycadman]

I have 2 navigation stations with a65, a95, 2xP70, 3xi70 and an evolution autopilot with a type 2 rotary drive, radar and all the bits to connect things together. Scenario : I'm sailing along tracking to a waypoint, cog and heading of 310 degrees, p70 displays 310 degrees and the plotter shows me sailing parallel to the coast. All is good. Suddenly the p70 displays 260 degrees, the chart plotter does a refresh and suddenly I'm heading for the shoreline. Cog and heading remain the same and the vessel does not alter course. This lasts from a few seconds to a minute before rectifying itself. The evolution sensor pack is not mounted near anything that may provide interference. This is something that started happening recently.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Rod,

The reported symptom may be indicative of a problem with the software within the system's devices, a problem with the location of the source of GPS data for the system (may require that an external GPS sensor be installed in a location affording it an unobstructed view of the skies overhead, a problem with the source of GPS data for the system, or a problem with the system's Data Master MFD which is sending navigational data to the autopilot. Accordingly, the first step would be verify that each of the components within the system has been updated with the latest available Raymarine product software updates. Please note that any update to the autopilots software will require that an Autopilot Factory Reset be commanded and that the actions specified within the FAQ found here be undertaken afterwards. Please additionally verify that the MFD which has the least obstructions to the skies overhead has been designated at the system's Data Source for GPS data, Time & Date, and Datum. Should the problem persist afterwards, then respond with:
- the Diagnostics...html file for this system
- photos of the EV-1 CCU and the surrounding area (at least 3' in all directions
- photos of the GPS data source's installation location to include surrounding and overhead structures.

[roycadman]

Chuck

Thanks for the reply. The a97 chartplotter is the master with the GPS enabled and is located outside at the helm. The other chart plotter is the slave, GPS disabled, a Raymarine switch connects the two plotters. All instruments have the latest software, albeit over two years old as there are no longer updates for this chartplotter. The autopilot ACU400 is mounted inside the saloon adjacent to the rotary drive, behind a protective panel, the sensor pack is mounted on the opposite side of a wooden panel, behind the trash can. There are two other pictures attached, showing the behavior, taken less than one minute apart. There is an external GPS mounted just to the side of the a97 that is connected to the AIS650 only. I have attached 5 pictures to this reply.

Regards
Roy

[Chuck - Raymarine - Moderator]

Roy,

The COG (green vector) appears to be fine. However, there definitely appears to be something wrong with the heading (magenta vector) supplied to the system. As the heading is changing as shown within the photos, it is recommended that you inspect the areas above, behind, and to the sides of the EV-1 CCU to ensure that none of the magnetic field producing items within the FAQ found here are within three feet. If so, then move the items or relocate the EV-1 CCU. It is also recommended that you verify that the autopilot has been updated with the latest available Raymarine product software updates and if not, the software within these items be updated accordingly. Upon completion of the latter and whether or not a software update was required, it is recommended that the actions specified within the FAQ found here be undertaken. Upon completion of these actions and should the reported symptom persist, then please respond with the value of the maximum deviation detected by the autopilot (MENU->SET-UP->DIAGNOSTICS->ABOUT PILOT->DEVIATION).