JMC NT–2000 - INS Port Data and Command Sentences

NT-2000 REF Manual
Installation
7-15
7.4. INS Port Data and Command Sentences
The equipment supports the following IEC 61162–1 data sentence formats for
communications with an INS / IBS system via the RS–422 port. It is assumed that the
port is set to ON via the procedure given in paragraph 4.11.2.2.
7.4.1. Received NAVTEX Sentence Format
The first line of a NAVTEX message text will be output in the following format.
$CRNRX
,
XXX
,
XXX
,
XX
,
aaxx
,
X
,,,,,
X
.
X
,
X
.
X
,
A
,
c-----c
*
hh <CR> <LF>
① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩
①Number of sentences 001 – 999
② Sentence number 001 – 999
③ Sequential message number 00 – 99 (
used to uniquely identify messages of same ID)
④ NAVTEX message ID characters (B
1
, B
2
, B
3
, B
4
)
⑤Frequency index:
0 = not received over air, 1= 490 kHz, 2 = 518 kHz, 3 = 4209.5 kHz
⑥ Null fields (
UTC is not supported. See NOTE 1. )
⑦ Total number of characters in this series of NRX sentences
⑧ Total number of bad characters
⑨ Status indication:
･ Status “A”= reception of NAVTEX message in correct format
･ Status “V”= reception of NAVTEX message in incorrect format
⑩ Message body (first line of message text characters). A forced carriage return (
 )
will be replaced with an underscore ( _ ) (
hex 5F ). See NOTE 2 for information on
the output format for undefined ASCII characters (
IEC 61162–1, paragraph 5.1.3)
Fields ④, ⑤, ⑥, ⑦, ⑧ and ⑨ are not output for the rest of the message lines. The
rest of the lines are therefore output as follows:
$CRNRX
,
XXX
,
XXX
,
XX
,,,,,,,,,,
c
-----
c
*
hh <CR> <LF>
NOTES:
1: The equipment does not have a realtime clock (RTC) and does not, therefore, use
UTC as the time source. To check message aging, an internal time reference derived
from the CPU clock (24.00 MHz) by frequency division is used.
2: Undefined characters used in a displayed/stored NAVTEX message are communicated
to the INS port in hexadecimal form using code delimiter (
^ , hex 5E) as follows:
･
*
1
Comma (
,
):
^
2C
･
*
2
Error character asterisk (
*
):
^
2A
･
Carriage return < CR > and line feed < LF >:
^
0D
^
0A
*
1
: To discriminate from field delimiter
*
2
: To discriminate from checksum field delimiter