ComNav Commander P2 - Sentences Transmitted; Heading & Status; Heading Output

ComNav Commander P2 & P2VS Installation & Operation Appendices
Document PN 29010074 V4.1 - 188 -
Sentences Transmitted
Heading & Status
In normal operation, the P Series SPU outputs NMEA 0183 formatted data at 4800 Baud, on
the OUT A & B pins of the SPU’s J9 – NAV I/O connector. This data may be used by
NMEA 0183 Listeners, or may be used to observe & record the autopilot’s operational data
for diagnostic purposes, while the system is running.
The sentences output by the P2 are:
• HDG (Heading, Deviation & Variation) – output 9 times per second.
• HDM (Heading, Magnetic) or HDT (Heading, True) – output 9 times per second.
Which one is being put out depends on the type (Magnetic or True) that the autopilot
is currently using for the source of Heading. If the source is NAV1 or NAV2, it also
depends on the setting of the NMEA Heading Type parameter.
• HTD (Heading/Track Control), or PCMNS (ComNav-proprietary Status sentence, see
below) – output once per second.
HTD is output for all Vessel Types, except sailboats; PCMS is output for sailboats
only.
• The Talker Identifier is AP, in all cases.
• All sentences have valid checksums.
The P2VS is the same, except that it never outputs HTD – instead, it always puts out
PCMNS, for all Vessel Types.
Heading Output
Here is one second of typical Heading output, on a P2VS system equipped with an RFU.
The boat’s current Heading is ~347° Magnetic, from an Analog compass.
$APHDG,346.5,,,,*5C
$APHDM,346.5,M*37
$APHDG,346.6,,,,*5F
$APHDM,346.6,M*34
$APHDG,347,,,,*46
$APHDM,347,M*2D
$APHDG,347.1,,,,*59
$APHDM,347.1,M*32
$APHDG,346.7,,,,*5E
$APHDM,346.7,M*35
$APHDG,346.9,,,,*50
$APHDM,346.9,M*3B
$APHDG,347,,,,*46
$APHDM,347,M*2D
$APHDG,346.7,,,,*5E
$APHDM,346.7,M*35
$APHDG,346.9,,,,*50
$APHDM,346.9,M*3B