DMU380SA Series
User’s Manual
________________________________________________________________________
Doc# 7430-0026 Rev. 01
Page 30
masterFail error during an over-range condition and continue to operate with this flag until
a quasi-static condition is met to allow for an algorithm restart. The quasi-static condition
required is that the absolute value of each low-passed rate sensor fall below 3 deg/sec to
begin initialization. The system will then attempt a normal algorithm start.
Dynamic
Motion
ON
The default setting is ON for the VG380SA. Turning off the dynamic motion setting results
in a higher gain state that uses the accelerometer feedback heavily. During periods of
time when there is known low dynamic acceleration, this switch can be turned off to allow
the attitude estimate to quickly stabilize.
Turn Switch
threshold
10.0
deg/sec
With respect to centripetal or false gravity forces from turning dynamics (or coordinated
turn), the VG380SA monitors the yaw-rate. If the yaw rate exceeds a given Turnswitch
threshold, the feedback gains from the accelerometer signals for attitude correction are
reduced because they are likely corrupted.
BIT
See 4.3.2
4.3.2
VG380SA Built-In Test
As with the IMU380SA, the VG380SA Built-In Test capability allows users of the
VG380SA to monitor health, diagnostic, and system status information of the unit in real-
time. The Built-In Test information consists of a BIT word (2 bytes) transmitted in every
measurement packet.
In addition, there is a diagnostic packet ‘T0’ that can be requested
via the Get Packet ‘GP’ command which contains a complete set of status for each
hardware and software subsystem in the VG380SA. See Sections 6 and 7 for details on
th
e ‘T0’ packet.
The BIT word contained within each measurement packet is detailed below. The LSB
(Least Significant Bit) is the Error byte, and the MSB (Most Significant Bit) is a Status
byte with programmable alerts. Internal health and status are monitored and
communicated in both hardware and software. The ultimate indication of a fatal problem
is the masterFail flag.
The masterStatus flag is a configurable indication that can be modified by the user. This
flag is asserted as a result of any asserted alert signals which have been enabled. See
Advanced BIT (Section 9) for details on configuring the masterStatus flags. Table 11
shows the BIT definition and default settings for BIT programmable alerts in the
VG380SA.
Table 11.
VG380SA Default BIT Status Definition
BITstatus Field
Bits
Meaning
Category
masterFail
0
0 = normal, 1 = fatal error has occurred
BIT
HardwareError
1
0 = normal, 1= internal hardware error
BIT
comError
2
0 = normal, 1 = communication error
BIT
softwareError
3
0 = normal, 1 = internal software error
BIT
Reserved
4:7
N/A
masterStatus
8
0 = nominal, 1 = one or more status alerts
Status
hardwareStatus
9
Disabled
Status
comStatus
10
0 = nominal, 1 = No External GPS Comm
Status
softwareStatus
11
0 = nominal, 1 = Algorithm Initialization or High Gain
Status
sensorStatus
12
0 = nominal, 1 = Sensor Over Range
Status
Reserved
13:15
N/A
