Airmar PB200 - Manual (Page 25)

PB200 WeatherStation User Manual revision 1.000
Proprietary and Confidential
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The azimuth offset angle, along with the pitch and roll offset angles, are also used to adjust the reported pitch and roll values in the transmitted PGN 127257, and in the transmitted
NMEA 0183 $WIXDR sentence. A properly set azimuth offset angle will allow the unit to accurately report pitch and roll of the vessel, even though the orientation mark on the
sensor housing may not be facing precisely toward the bow.
The recommended procedure to set these offsets is as follows:
1. If the unit is mounted on a vessel, this procedure should be performed with calm water and no wind, and with the vessel at rest.
2. First, zero out all offsets by using the Command Group Function PGN 126208, specifying the individual fields in PGN 126720-32 as follows.
PGN 126720
Field Value
1 135 (decimal)
3 4 (decimal)
4 32 (decimal)
5 0
6 0
7 0
3. Determine the desired azimuth offset angle, and program this into the sensor using the Command Group Function PGN 126208, specifying the individual fields in PGN
126720-32 as follows. The pitch and roll offset fields should be omitted for this step (or set to zeroes).
PGN 126720
Field Value
1 135 (decimal)
3 4 (decimal)
4 32 (decimal)
5
Azimuth offset angle
of sensor, relative to
bow
4. Allow the vessel to stabilize to its "level" state, and then read the values of pitch and roll that are reported by PGN 127257. If the vessel is rocking back and forth, then
take a number of readings and calculate an average for both pitch and roll.
5. Program the negated versions of these measured pitch and roll values back into the unit as offsets using the Command Group Function PGN 126208, specifying the
individual fields in PGN 126720-32 as follows. Note that field 5, azimuth offset angle, is not programmed during this step.