Data collection to diagnose autopilot performance issues

Autopilots are complex systems whose behavior depends on input from multiple sensor data streams, vessel speed, steering characteristics, and much more, as well as weather and sea conditions. If an autopilot does not steer well, there are many potential causes that should be checked before assuming it is a fault. In fact, the current Evolution autopilots are brilliant and very reliable, so if yours is not working well, it is almost certainly a problem with its settings or incoming data, which we can help find and resolve.

Some other common questions address common causes of steering problems, but if it is not something simple like this, what can be done to understand the problem and the cause? The answer is to collect a recording of NMEA2000/SeatalkNG data while the autopilot is in use and the problem is apparent.

What should I do before making a SeatalkNG data recording?

There are some common things to check first, before going to the trouble of recording SeatalkNG data (Calibration Lock must be set to Off in Vessel Settings to access many of these settings):

1. Hard-over time
   In autopilot systems that do not have a rudder reference sensor, such as EV-100 and EV-200, the Hard-Over time calibration option is very important for good steering performance. This setting is found in Menu > Setup > Autopilot calibration > Drive settings. The default value is 10 seconds, but this may be wrong for your boat's steering. If you change the current value by a few seconds, how does this affect the steering? If your boat's steering is faster or slower than normal, this setting tells the autopilot and it can then steer a straighter course.
   
   
2. Speed data
   The autopilot uses speed information to determine how much rudder to apply. What is the current speed input selection in Autopilot calibration > Vessel Settings? Generally, Speed Over Ground (SOG) from your chartplotter gives the best result.
   
   
3. Vessel type
   Sometimes the choice of vessel type that gives the best steering performance is not the obvious choice in Autopilot calibration > Vessel Settings. I would suggest trying each sail or motor type, even if they do not seem to be the right type for your boat, as one may give a better "description" of how your boat handles than others and thus result in better steering performance.
   
   
4. Software version
   You should ensure that your autopilot is running the latest version of the software, as we have made many performance improvements over time. Even if the autopilot is new, it may have been in stock for some time and may be running older software. You can update the software through any of the latest Raymarine multifunction displays or through the Wifi software update feature on the latest Raymarine MFDs.
   
   
5. Compass calibration
   I would suggest doing Autopilot calibration > Vessel Settings > Restart Compass, to ensure that any bad compass calibration data (e.g., from when something magnetic was near the heading sensor) is removed and you can start over. You should always do this after moving the heading sensor or changing anything in its environment or surroundings.

If these do not solve the problem, you should record SeatalkNG data while the autopilot is in use and send this to Raymarine Support via Ask Raymarine.

Why is it useful to record SeatalkNG data?

A verbal description of how an autopilot works is very difficult to convey clearly, but in a data recording, there is timestamped data showing:

• The autopilot's heading versus GPS course over ground
• Speed through water versus speed over ground
• Autopilot mode (Standby, Auto, Vane, Track, Calibration)
• Requested and actual rudder angles and rudder speed
• Vessel yaw rate
• Vessel pitch and roll, wind data
• Any autopilot alarms and error messages
• Course and distance to waypoint, cross-track error
• Product part number, serial number, and software versions

And much more. In other words, if you can log that data and send it to us, we can "replay" your trip, see how the autopilot and vessel performed almost as if we were on board ourselves, and graphically show which combination of data over time.

What should you do?

1. Turn on the autopilot's "debugging" in Setup > Calibration > Commissioning. Set Debug to 7 and ACU Debug to 31. To see these options, Calibration Lock (in Vessel Settings) must be Off.
   
   
2. Insert a blank MicroSD card into a chart slot in a Raymarine Lighthouse2 or Lighthouse 3 MFD (if you have more than one MFD, this must be the Master unit connected to STNG).

On Lighthouse 4 MFDs:

1. Go to Home > Settings > Network > Diagnostics > NMEA devices and messages (if you do not see this option, make sure your display is running a new version of the software and that you are working on the Master display), select where you want to save the recording with Save to:, then press Start Recording.
   
   
2. Press Back (<) once to go to the NMEA devices page and press Refresh to get the system to poll all NMEA2000 devices, which will then appear in the recording.

On Lighthouse 2 MFDs:

1. Go to Home > Setup > Maintenance > Diagnostics > Interfaces > Record File and make sure the correct location is selected (1 is top), then go to N2K/STng > Buffer > Start Buffer > Record Buffer.
   
   
2. Go to Home > Setup > Maintenance > Diagnostics > Select Device. This gets the system to poll all NMEA2000 devices, which will then appear in the recording.

Once the recording has started:

1. Use the autopilot as long as you need to demonstrate the problem. You must be underway, and you must log at least several minutes of data. If you log for a long time, please note when we can expect to see the problem (e.g., 16:30 or 25 minutes into the log).
   
   
2. Go back to MFD diagnostics and stop the log recording.
   
   
3. Turn off Debug Mode on the autopilot.
   
   
4. Ask a question here, describe the problem, and attach all NMEAxxxxxx.log files you find on your MicroSD card. It is important to tell us what to look for in the log.

If you do not have an LH2 or LH3 MFD

Many Raymarine technical service dealers have hardware that can make recordings, or we may be able to provide a "data logger" that can do the same. If you think you may need to go this route, contact technical support.

Which autopilots is this process useful for?

All SeatalkNG-connected autopilots: SPX autopilots with color pilot displays and the Evolution autopilot series.

What should I do once I have created a log/recording of the autopilot's performance?

You should send this to Raymarine technical support, along with a description of the problem, via Ask Raymarine.