Raymarine HSB Chartplotter, User Manual

Page: 104 / 154

Chapter 5: Setting Up the Chartplotter 87
This setting does not affect the default soft key labels, which are
controlled by the Soft Keys option previously described.
Units
You can set the units for distance, speed, depth and temperature. The
units you set will be used to display all data, including information
received from other instruments on the system. However, the distance
units do not affect the chart scale, which is always in nautical miles.
Variation Source
The variation value is the difference between True and Magnetic
direction data for heading or bearing values. The Variation Source option
provides soft keys for selecting Auto or Manual variation mode, displays
the current variation value for each and highlights the currently selected
mode.
Auto Mode
If you select Auto mode, the chartplotter obtains the value of variation
automatically, normally from received SeaTalk or NMEA data. The
variation value that is used depends on the data available, and is
selected in the following order of priority:
1. Variation value from the same source as the heading data:
- If heading data is being taken from NMEA, then variation is also
taken from NMEA
- If heading is taken from SeaTalk, then SeaTalk variation is used
2. Variation value from a different source:
- If heading data is being taken from NMEA, but no NMEA
variation is available, then variation is taken from SeaTalk
- If heading is taken from SeaTalk, but no SeaTalk variation is
available, then variation is taken from NMEA
3. A calculated variation value, using position data, if no SeaTalk or
NMEA value is available
4. The current manual variation value, if no SeaTalk or NMEA value
and no position data is available
System
Parameters