Table 9 - Nmea Sentence Priority - ComNav Commander P2 Installation & Operation Manual

ComNav Commander P2 Installation & Operation
All sentences received must have valid checksums. Sentences which do not have any
checksums, or have invalid checksums, will be ignored. In some cases, if the missing/invalid
condition persists long enough, an INVALID CRS DATA, SPEED DATA, &/or HEADING error
will occur (see page 170).
A number of the various data values used by the autopilot can be received in one or more
different sentences (for example, Speed can be received in VTG, VHW, VBW, RMA or RMC).
If a particular data value is received in more than one sentence, then the value in the
highest-priority sentence – per the table below –will be the one used by the autopilot.
Magnetic heading
True heading
Magnetic heading,
Magnetic variation
Range to waypoint
Vessel speed
Vessel speed
Vessel speed
Bearing origin to destination magnetic and true,
Waypoint ID
Cross track error
Cross track error,
Arrival circle entered
Bearing origin to destination magnetic or true,
Waypoint ID
Course to steer magnetic and true
Cross track error,
Waypoint ID,
Range,
Bearing present to destination true,
Arrival circle entered
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
Vessel speed
Vessel speed,
Magnetic variation
Latitude and longitude
True wind angle & speed
Apparent wind angle & speed
True or Apparent wind angle & speed

Table 9 - NMEA Sentence Priority

Document PN 29010074 V3.1
Data Used
- 166 -
Sentence
Priority
Sentence
(larger number is
higher priority)
*HDM 1
*HDT 2
*HDG 3
*BWC 4
*VTG 5
*VHW 6
*VBW 7
*BOD 8
*XTE 9
*APA 10
*HSC 11
*RMB 12
*APB 13
*RMA 14
*RMC 15
*GLL 16
*VWT 17
*VWR 18
*MWV 19
Appendices