POS MV V4 User Guide
Fault Identification
Copyright © Applanix Corporation, 2009
9-19
IMU
Simultaneously, it increments a counter that keeps track of the
number of bad IMU frames. The Fault Detection window shows
the count of Bad IMU Frames in its bottom left-hand corner.
• An occurrence of several consecutive bad IMU frames will cause
POS MV to reinitialize and start coarse levelling. However, due to
the communications handshaking used by the IMU, bad IMU
frames are highly unlikely.
If bad IMU frames do occur, their likely cause is one of the following:
• Problems in the data cable that connects the IMU to the PCS
• Problems with the IMU or the power supplied to the IMU
• Problems within the PCS
Loss of Calibration
If IMU performance falls below specification (as may happen if the
IMU experiences excessive shock or vibration), the IMU Status field
on the controller main window will indicate an IMU failure.
Refer to the Fault Detection and the Message log windows
(described in
Fault Detection on page 9-7 and Message Log on page
9-11) for a more detailed identification of the fault.
Note: If POS MV detects that the IMU performance is outside
specification, it will alert you and continue navigation.
If POS MV detects a hardware failure in the IMU, the controller main
window will display the warning message IMU Failure. Note any
indications on the Fault Detection or the Message Log windows, and
contact Applanix for advice.
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