Kongsberg Seapath 320, Руководство по установке, Страница: 118 / 152

Seapath 320
102 M300-62/rev.2
A.8 Lehmkuhl gyro repeater format 12
This Lehmkuhl gyro repeater format is used when outputting heading from Seapath to
Lehmkuhl gyro repeaters. The messag is similar to the HDT message output in the
standard NMEA format from Seapath. The main differences are lower resolution and no
checksum.
When heading is output to devices, which are compliant to the NMEA specification [1],
it is recommended to use the standard NMEA format and not the Lehmkuhl format.
A.9 1PPS time tag, NMEA ZDA message
This 1PPS time tag message is output once per second, approximately 0.5 seconds
before the time pulse. The message format is ASCII text using the ZDA message
defined in [1]. The message contains the UTC time when the message is output. The
next time pulse appears at the first integer second after the time in the message.
Format: $INZDA, time , day , month , year ,,* csum term
Explanation:
time UTC time on format hhmmss.ss where hh is hours (00 - 23), mm is
minutes (00 - 59) and ss.ss is seconds (00.00 - 59.99).
day Day of month (01 - 31).
month
Month of year (01 - 12).
year Year on format yyyy.
csum Checksum (exclusive or) of all characters between, but not including, the
preceding
$ and * , hexadecimal (00 - FF).
term CR-LF (two bytes, values 13 and 10).
This format is recommended used together with 1PPS signal output on the BNC
connector at the rear of the Processing Unit. This since the message is output
synchronised with the 1PPS signal and is easier/faster to decode than the standard
NMEA output with a number of NMEA messages included.