7
3 Output formats available from compass
3.1
NMEA-0183
The serial output format is: 4800 Baud, 8 data bits, 1 stop bit, no parity.
The compass sends information using the standard NMEA-0183 sentence ‘HDG’: Magnetic
Heading, Deviation, and Variation. But note that the information of Deviation and Variation is
not sent and so blank fields are defined by consecutive commas. In the A5022 the sentence
may have one of several forms typically of the general form:
$HCHDG,hhh.h etc
Where
hhh.h
is the magnetic heading from 000.0 to 359.9 degrees
Also the Rate-of-turn data is sent either with or without the heading sentence.
For a complete list of output formats available see Section 5
3.2 Furuno AD-10
The compass has a separate, dedicated output in Furuno AD-10 format. This is a proprietary
4 character serial format, which gives heading in degrees and tens of minutes. The string
0872 represents the heading 87° 20’ so that the precision is to 1/6 of a degree. At the
same time the A5022 would be also sending the NMEA data to a precision of 1/10 of a
degree.
480
µ
s
100ms minimum
Duration of data is 16 clocks each
high=low=30
µ
s. Total = 480
µ
s.
Frequency of data packets is set by
the interval command. Max = 10Hz
Clock
Data
Fig 4
