Jeppesen Nobeltec SSHS, Owner'S Manual

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CALIBRATION
Jeppesen Marine
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2. Transmit the Heading True (HDT) sentence using variation data as manually entered
over the NMEA 0183 interface if HDT is enabled (see
Appendix A
for enabling or
disabling NMEA 0183 sentences).
3. Transmit over the NMEA 2000 interface the Magnetic Variation PGN (127258) with the
Variation Source field value corresponding to the manually entered variation. The
PGN’s Variation Source field will be transmitted with the lowest possible quality
indicator, which is “Manual Entry”.
Warning:
Magnetic variation changes as your position on the earth changes;
therefore, the variation should be adjusted with changes in position. The SSHS will
not automatically adjust variation with changes in position; it is the responsibility of the
user to adjust variation with changes in position.
Variation Source Selection
As shipped from the factory, the SSHS automatically looks for variation from both the NMEA
0183 and NMEA 2000 interfaces. If there is only a single source of variation available (either
the NMEA 0183 or the NMEA 2000 interface), then there is no need to manually select a
variation source. However, if there are multiple variation sources (i.e., from both the NMEA
0183 and NMEA 2000 interfaces), or there is no source for variation, then it is necessary to
select a specific variation source.
The SSHS can be programmed to use one of three possible variation sources:
• Variation from only the NMEA 0183 Interface
• Variation from only the NMEA 2000 Interface
• Variation from only Manual Entry
You can program the SSHS to accept a specific source for the variation data through the
NMEA 0183 Interface. See
Appendix A
for details on programming the SSHS to use a
specific variation source.