MTS WIFT Mini Transducer Interface User Manual
Page 82
SWIFT
®
Mini TI
82
Troubleshooting
Shunt Calibration as
Recorded by External Data
Acquisition is incorrect or
inconsistent. (The internal
shunt check in the TI
electronics verifies each of
the eight individual
bridges, but it is the six
bridge 10 V output that you
can record if desired.)
The gains have been
changed in the calibration
file.
As the bridges are shunted, the eight raw bridge
outputs pass through the TI box and have the
calibration gains applied to them. If the
calibration file has been changed or modified,
the six bridge 10 V outputs will reflect this. Use
the TI2XFER utility to verify that the
calibration settings portion of the calibration file
matches the original, and download the original
to TI if needed.
Data acquisition
configuration, settings,
offset, or scaling is
incorrect, changed, or
inconsistent
Investigate the data acquisition system to verify
that it is configured properly.
The output signal polarity
is incorrect
The Polarity setting for one
or more axes is incorrect
Check the polarity for each axis in the
calibration file and compare it with the desired
configuration as described in the
Reference Angle is 180° off.
If the reference angle is 180° off, the output
polarity of some channels may appear to be
reversed. The reference angle can be verified as
described later in this table.
Reference Angle is
incorrect
Zero was done with anti-
rotate device not attached,
or attached with orientation
different than test set-up.
Make sure that the anti-rotate and slip ring
assembly are securely fastened during the
spinning zero procedure. If the anti-rotate or slip
ring is removed or rotated from the transducer,
rezeroing the transducer angle is required.
Spinning Application:
Vehicle Coordinate System
Outputs have unusual or
incorrect waveform shapes
to them. (Angular output
may need to also be
recorded to troubleshoot
based on per-revolution
outputs)
A one-time-per-revolution
of tire signal appears while
the vehicle is driving
straight on a flat surface.
The mean level on FX and
FZ is equal to zero, and the
amplitude is fairly
consistent during straight
driving on a flat surface.
The amplitudes on FX and
FZ are about the same and
equal to the vehicle weight.
Angle Mode: Check that the AngleMode value
is set to zero in the TI calibration file as
accessed by the TI2XFER utility.
AngleMode=0 sets the TI to use the encoder to
give angular transformation to the spinning
signal, to provide non-spinning vehicle
coordinate system output.
Angle Input: Verify that the encoder output is
present. The Angle output from the TI box
should be a 0 to 5 V sawtooth output. If this
signal is not present, check that the encoder and
slip ring assembly has not been damaged. To
verify if encoder damage is suspected, swap the
slip ring assembly with a known functioning
unit to verify. If the slip ring/encoder assembly
is damaged call MTS or replace it with spare
slip ring assembly if available.
Troubleshooting Guide (part 9 of 11)
Symptom
Possible Causes
Solution