GUIDANCE MARINE CyScan, Руководство по установке

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DP Message Types (Continued)
MT Custom DP String
The MT Custom DP String adopts NMEA0183 conventions with a minimum length of 63 and maximum length of 80 characters. When multi-target tracking, multiple
messages are emitted per rotor revolution: one for each target in the tracking group.
$PGNMT,T,HH˽MM˽SS.SSS,[NNNN]N,E,[IIII]I,S,[RRR]R.RR,Z
R
.Z
R
Z
R
,[BB]B.BB,Z
B
.Z
B
Z
B
,[Q]Q,[AAA]A,XXXX*CC<CR><LF>
Where:
•
$PGNMT
Proprietary header 6 chars
•
T
Type field for CyScan [C] 1 char
•
HH_MM_SS.SSS
Real-time clock time at message transmission to DP 12 chars
•
[NNNN]N
16-bit revolution counter in decimal 1–5 chars
•
E
Sequence identifier 1 char
•
[IIII]I
CyScan Responder ID [1-5] or RadaScan 16 bit Responder ID 1–5 chars
•
S
Status [V]oid or [N]avigating 1 char
•
[RRR]R.RR
Range in metres 4–7 chars
•
Z
R
.Z
R
Z
R
Range standard deviation in metres 4 chars
•
[BB]B.BB
Bearing in degrees (clockwise from bow) 4–6 chars
•
Z
B
.Z
B
Z
B
Bearing standard deviation in degrees 4 chars
•
[Q]Q
Target brightness [%] 1–2 chars
•
[AAA]A
†
Age of measurement in ms 1–4 chars
•
XXXX
Reserved – 16 bit flags in hex 4 chars
•
*
Delimiter 1 char
•
CC
Checksum 2 chars
•
<CR><LF>
Carriage return and line feed 2 chars
†
The ‘age’ is the accumulated time in milliseconds from the
moment the measurement was made until the moment the
message string is constructed, prior to being transmitted
to the DP system. It effectively gauges the lag through the
system, which may not be constant. Having a value for the
lag allows for subsequent correction of the measurement.