GUIDANCE MARINE RadaScan View, Installer'S Manual

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DP Message Types (Continued)
Rolls-Royce Custom DP String
The Rolls-Royce Custom DP String adopts NMEA0183 conventions with a minimum length of 82 characters and maximum length of 101 characters.
It provides the same type of information for both CyScan and RadaScan sensors, including range and bearing to all tracked responders (similar to the MDL multi-responder format).
It also provides quality information.
$PGNRR,T,YYYY˽MM˽DD,HH˽MM˽SS.SSS,[NNNN]N,[IIII]I,S,[RRR]R.RR,Z
R
.Z
R
Z
R
,[BB]B.BB,Z
B
.Z
B
Z
B
,[Q]Q,±[r]r.r,±[p]p.p,
[AAA]A,XXXX*CC<CR><LF>
Where:
•
$PGNRR
Proprietary header 6 chars
•
T
Type field indicating RadaScan system [R] 1 char
•
YYYY ˽ MM ˽DD
Real-time clock date at message transmission to DP 10 chars
•
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
•
[IIII]I
RadaScan 16-bit responder ID 1–5 chars
•
S
Status [V]oid, [A]vailable and [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
RadaScan SNR [dB] 1–2 chars
•
±[r]r.r
Sensor roll in degrees at time of measurement 4–5 chars
•
±[p]p.p
Sensor pitch in degrees at time of measurement 4–5 chars
•
[AAA]A
†
Age of measurement in ms at transmission time 1–4 chars
•
XXXX
Reserved – 16-bit flags in hex 4 chars
•
*
Delimiter 1 chars
•
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.
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