Table of Contents
Advertisement
1. PRINCIPLE OF NAVTEX SYSTEM
1.3
Message Format
For automatic identification of messages, each message starts with nine control char-
acters, called "Header codes".
The first five characters are always "ZCZC_" and common to all messages. This part
is used for message synchronization. The latter four characters are designed as B1,
B2, B3 and B4 indicate origin, category and serial number of the message.
Character B1 is the identification letter of the Navtex station "A" thru "Z". Character B2
indicates the type of message. "A" thru "Z", as listed below. Character B3 and B4 in-
dicate the serial number of the message. The serial numbers are counted up from "01"
to "99", and starts from "01" again. Number "00" is specially reserved for important
emergency messages.
The end of each message is indicated by "NNNN" (four successive N's). General mes-
sage format is summarized below.
ZCZC
Start code
(sync)
A:
navigational warning
B:
meteorological warning
C:
ice report
D:
search and rescue information/
piracy and armed robbery
E:
meteorological forecast
F:
pilot message
G:
AIS service message
H:
LORAN-C message
1-2
Header code
B1 B2 B3 B4
Serial number
"00":
"01" - "99": Normal message
Type of message
"A" - "Z"
(See the list below.)
Station ID
"A" - "Z"
[Type of message (category)]
main message
Main message
Emergency message
I:
reserved presently not used
J:
SATNAV message
K:
other electronic navigational aid sys-
tem message
L:
navigational warning (additional)
M to Y: reserved presently not used
Z:
QRU (no message on hand)
NNNN
Termination code
Advertisement
Table of Contents
