PNI FieldForce Trax - Manual (Page 32)

PNI Sensor Corporation DOC#1016505 r06
TRAX User Manual Page 28
However, the TRAX can store eight (8) sets of magnetic calibration coefficients and
eight (8) sets of accelerometer calibration coefficients. This feature is useful if the
compass will be placed in multiple locations that have different local magnetic field
properties. The default is index number 0 and initially this is populated at PNI with
factory-generated coefficients for the device itself. The other sets initially are
unpopulated.
To store a coefficient set, first select the index number (0 to 7), then perform a
calibration. The coefficient values will be stored in the defined index number,
assuming the is selected after the calibration. To recall and use a different set
of coefficients, change the “Mag Coefficient Set” and/or “Accel Coefficient Set”
number, then click the button.
Automatic Sampling
If selected, the TRAX will take a sample point once predefined minimum change and
stability requirements have been satisfied. If the user wants to have more control
over when the point will be taken then Auto Sampling should be deselected.
H/P/R Output During Cal
When selected, the heading, pitch, and roll of the device will be output below the
sample number during a calibration. Using this feature, the user can monitor the
device’s orientation to easily follow the appropriate recommended calibration pattern.
Since a calibration is being performed, these values are relative and should not be
considered accurate.
Audible Feedback
If selected, TRAX Studio will give an audible signal when a calibration sample is
taken.
6.5.2 Performing a Calibration
Before proceeding, ensure you are familiar with the recommended calibration pattern
corresponding to the “Type” selected. These are discussed in Section 5.
To perform a calibration, follow the following steps:
Click the button to begin the calibration process.
If “Automatic Sampling” is not checked the first sample will be taken
automatically assuming the TRAX is relatively stationary. After this, it is
necessary to click the button to take a calibration sample point.
This should be repeated until the total number of samples is taken, changing the
orientation of the device between samples as discussed in Section 0.