ComNav P4 - Page 173

ComNav P4 Installation and Operation Appendices
Document PN 29010100 V1r0 - 173 -
Data Used
Sentence
Sentence
Priority
(larger number is
higher priority)
Magnetic heading
*HDM
1
True heading
*HDT
2
Magnetic heading,
Magnetic variation
*HDG
3
Range to waypoint
*BWC
4
Vessel speed
*VTG
5
Vessel speed
*VHW
6
Vessel speed
*VBW
7
Bearing origin to destination magnetic and true,
Waypoint ID
*BOD
8
Cross track error
*XTE
9
Cross track error,
Arrival circle entered
Bearing origin to destination magnetic or true,
Waypoint ID
*APA
10
Course to steer magnetic and true
*HSC
11
Cross track error,
Waypoint ID,
Range,
Bearing present to destination true,
Arrival circle entered
*RMB
12
Cross track error,
Arrival circle entered,
Bearing origin to destination magnetic or true,
Waypoint ID,
Bearing present to destination magnetic or true,
Course to steer magnetic or true
*APB
13
Vessel speed
*RMA
14
Vessel speed,
Magnetic variation
*RMC
15
Latitude and longitude
*GLL
16
True angle and speed
*VWT
17
Apparent angle and speed
*VWR
18
True or Apparent angle and speed
*MWV
19
Table 9 - NMEA Sentence Priority
NOTE: the Heading value used by the P4 may be in Degrees Magnetic or True,
depending on which sentences are received (assuming all sentences have valid
data):
• If all of HDM, HDT and HDG are being received, or just HDT and HDG, or just HDM
and HDG, then the autopilot will use Magnetic Heading (indicated on the display by
an ‘M’ beside the Heading value – and will use the data value in the HDG sentence.
• If only HDM and HDT are received, or just HDT, then the autopilot will use True
Heading (indicated by a ‘T’), from the HDT sentence.