Table 3. Asynchronous Control Message (0X01 Format); Table 4. Asynchronous Control Message Field Status Word 1 - Honeywell HG4930 Installation And Interface Manual

HG4930 Installation and Interface Manual

Table 3. Asynchronous Control Message (0x01 Format)

POSITION PARAMETER
1 IMU Address
2 Message ID
3 Angular Rate X
4 Angular Rate Y
5 Angular Rate Z
6 Linear Acceleration X
7 Linear Acceleration Y
8 Linear Acceleration Z
9 Status 1
10 Status 2A or 2B
11 Checksum
Sum of all message data (positions
1...10 of this table), taken as 16 bit
words, and summed without regard for
rollover.
Total Length

Table 4. Asynchronous Control Message Field Status Word 1

BIT
Bit 0-1
Bit 2-3
Bit 4
Bit 5
Bit 6
Bits 7-10
Bit 11-14
Bit 15
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LENGTH
(BYTES)
1
1
2
2
2
2
2
2
2
2
2
20
DEFINITION
2 Bit Counter
2 bit BIT-mode indicator
IMU
These fault monitors are aggregate and latched (continue after the failure
Gyro
has stopped) but will only latch after a lower level test has failed. The
latching logic may require multiple consecutive failures before setting.
Accelerometer
Gyro Sensor
Bits 8-10 check that Gyros X, Y, and Z are individually functioning.
Reserved
IMU OK
LSB WEIGHT UNITS OR CONTENTS
N/A Constant 0x0E
N/A Constant 0x01
2 -20 * 600
2 -20 * 600
2 -20 * 600
2 -14 * 600 0.3048 meters/sec
2 -14 * 600 0.3048 meters/sec
2 -14 * 600 0.3048 meters/sec
N/A
N/A See Table 5 and 6
N/A // this pseudo code illustrates the checksum
for (i=0; i<9; i++) // (20-2)/2=9
{ u16sum += u16_msg_array[i]; }
Checksum = u16_msg_array[9];
if (Checksum != u16sum) {checksum error}
NOTES
00 01 10 11...
0=Power-up BIT
1=Continuous BIT
2-3 = Reserved
0=OK, 1=Failed
These latched failures are cleared after power up or reset.
0=OK, 1=Failed
Bit 7 checks sensor voltage levels.
N/A
0=OK, 1=Failed
8
rad/sec/LSB
rad/sec/LSB
rad/sec/LSB
2 /LSB
2 /LSB
2 /LSB
See Table 4
algorithm
u16sum = 0;