9
4.3 Terminating a bad calibration
If the process is faulty in any way – such as would happen if the manoeuvre cannot be
completed, the process can be terminated by the NMEA command listed and the original
factory default (linear) table is restored. Alternatively this can be done by pressing both
Switches together for at least 1 second.
NOTE that there should be a delay of at least 5 seconds after termination before a new
calibration process is initiated.
4.4 Setting reference NORTH heading
Switch 2 (and also a NMEA command) is provided to set ‘zero’. The A5022 should
a.
first be auto-calibrated
b.
then be aligned to North
4.5 Set-up suggestions
When the A5022 is fixed in place and connected it can be calibrated as described above.
Choose a calm day and a region of water where there are no currents. Set the boat
turning to left or right at a slow rate and fix the wheel or tiller. Then, when the turning is
steadily under way, press the auto-calibrate button and watch the LED.
When calibration is completed the boat can be on its way and the next task is to set North.
This is best done by identifying transits on a chart and heading the boat on the transit.
Again this should be done in the same conditions so that the heading can be lined up on
the transit and maintained while the set-zero button is pressed.
