SRT AIS, Installation And Operation Manual

Page: 71 / 92

Technical Information
Page 69
Table 9 Port Priority Order
6.11.1 Position Priority Scheme
Position information is taken from the highest priority source reporting DTM
with WGS84 or datum override and RMC. If no RMC sentences are available,
position shall be taken from the highest priority source reporting DTM with
WGS84 or datum override and any one of:
• GGA
• GNS
• GLL
The following sentences are only processed only if they are from the currently
selected position source:
• RMC
• GGA
• GNS
• GLL
• GBS
• GRS
• GSA
• GSV
• GFA
When no position has been received on the selected port for 30 seconds, the
port is deselected as a position source, and a new source selected as de-
scribed above.
6.11.2 Course and Speed Priority Scheme
COG and SOG are taken from the highest priority source reporting any one of:
• RMC (with DTM=WGS84 or datum override)
• VTG
• VBW
VTG and VBW are only processed if they are from the currently selected COG
& SOG source. When no COG+SOG has been received on the selected port
External Display 4
Pilot 5
Long Range 6
Port Priority (1 = highest)