PNI Legacy Comm Board - Manual (Page 26)

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mpcal (Multi-Polled Calibration Enable)
Enables the multi-polled calibration.
Note: For modules that do not have an onboard processor (for example, the MicroMag), the
CommBoard will calculate and output this data
2-Axis Compass Calibration using the CommBoard
Calibration is the process used with PNI sensor technology to separate the earth’s magnetic field
from magnetic field distortions. Magnetic field distortions are created by the environment into
which the sensors are mounted. By implementing a simple calibration routine with the sensors in
a fixed position within the host system, the maximum and minimum strength fields can be deter-
mined and then used to correct the sensor output for the distortions present. A calibration should
be performed under the following conditions:
•
when the unit is first installed into a host system.
•
when the unit is moved.
•
when the unit indicates that it is in need of a calibration.
Follow the steps below to perform a calibration.
1. Place the unit to be calibrated into the host system.
2. Set the unit at its intended operating position in as level of a position as possible.
3. Sent the Multi-Polled Calibration Enable (mpcal=e) command. This enables the calibration
routine.
4. Send the Go Command
5. Rotate the unit through two 360 degree circles while maintaining a level position. The
rotations should be no faster than 30 seconds each to achieve the highest possible accuracy.
6. Send the h command
7. Send the Multi-Polled Calibration Disable (mpcal=d) command. This disables the calibration
routine.
8. Send the Save Settings (save) command to save the calibration information to the
CommBoard and the attached module, where applicable.
Syntax:
mpcal
Response Format: $mpcal{value}*
Valid Values:
d disabled (default)
e enabled
Query Syntax: mpcal?
CommBoard
Module Commands