Download FA-50 Servicemanual

8.1 For Service
7. External GNNS
This setting is used to determine whether or not to use a position data from the external
GPS. No connection to the external GPS should require a setting of “Don’t use”.
For AIS in Class B, the External GNNS data is not mandatory.
The position data sentences of GNS, GGA, RMC, and GLL are acceptable. Priority of
these sentences is same as described in “4. EPFS Alarm” on page 8-6. Priority of GNSS
to be retrieved is described below:
external DGPS > built-in DGPS > external GPS > built-in GPS
Note:
If the built-in GPS does not determine positions, no external GPS data is used.
- Use
Determines that the external GPS is used.
- Don’t use
Determines that no external GPS is used.
Tips: Requirements when data from the external GPS is used
1) The datum of the external GPS should be WGS84, where the DTM sentence is
outputted and the coordinates of WGS-84 are determined.
2) A valid RAIM sentence (GBS) should be received and expected deviations of the
latitude and longitude should be less than 10 m.
3) The external GPS-determined position should be within 26 m of the built-in
GPS-determined position.
4) The data format complies with IEC61162-1 including Mode Indicator and Check
Sum.
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