MRU
Demo Program Manual
Inertial Labs, Inc
TM
Address:
39959 Catoctin Ridge Street, Paeonian Springs, VA 20129 U.S.A.
Tel: +1 (703) 880-4222, Fax: +1 (703) 935-8377
Website:
www.inertiallabs.com
106
7.
P_bar or Hs – pressure or Significant Wave Height, see section 10.2.3.
8.
H_bar is barometric height.
9.
The low byte is transmitted by first.
Table C.5
.
The message payload at MRU Minimal Data format
Byte
number
0 – 1
2 – 3 4 – 5 6 – 11
12 –
17
18 –
23
24–27
28 –
29
30 – 31 32 – 33
Parameter Heading Pitch Roll
GyroX,
GyroY,
GyroZ
AccX,
AccY,
AccZ
MagX,
MagY,
MagZ
Heave USW Vinp Temper
Length
2 byte
word
2 byte
sword
2 byte
sword
3
2 byte
sword
3
2 byte
sword
3
2 byte
sword
4 byte
integer
2 byte
word
2 byte
word
2 byte
sword
Note
Orientation angles,
deg*100
Angular
rates,
deg/s
*KG
Accele-
rations,
g*KA
Magne
tic
fields,
nT/10
m*100
Supply
voltage,
VDC*
100
Temper
ature,
ºC*10
Notes
1.
Values of KG, KA are scale factors depending on gyro and accelerometer range:
Gyro range, deg/sec 250 or 300 450 or 500 1000 2000
KG
100
50
20
10
Accelerometer range, g
2
6
8
10
15
KA
10000 5000 4000
2000 2000
2.
Angular rates, linear accelerations and magnetic fields are in the carrier object axes
(X is lateral axis, Y is longitudinal axis, Z is vertical axis). The MRU orientation
relative to the carrier object axes is set by alignment angles (see Appendix E.
Variants of the Inertial Labs
TM
MRU mounting relative to the object axes).
3.
USW is unit status word (see Appendix D. The Unit Status Word definition, for
details).
4.
Temper is averaged temperature in 3 gyros.
5.
The low byte is transmitted by first.
At the
«MRU NMEA»
output data format the MRU data are transmitted in
the form of sentences with printable ASCII characters like the NMEA 0183
format. Each sentence starts with a "$" sign and ends with <CR><LF>
(carriage return 0xD and line feed 0xA symbols). All data fields are
separated by commas. The general form of the «MRU NMEA» sentence is
the next
$PAPR,AAAA.aa,B,RRRR.rr,PPP.pp,HHH.hh,TTT.t,V.vv,SSSS*CC<CR><LF>
where PAPR is identifier and other fields are listed in the Table C.6.
