PNI FieldForce Trax - Manual (Page 51)

PNI Sensor Corporation DOC#1016505 r06
TRAX User Manual Page 47
kSetResetRef (frame ID 110
d
)
This frame re-aligns the TRAX 9-axis heading to the 6-axis (mag and accel) heading
and establishes the criteria for the reference magnetic field. The frame should be sent
when the user is confident the local magnetic field is not distorted. It has no payload.
7.5.2 Data Acquisition Parameters
kSetAcqParams (frame ID 24
d
)
This frame sets the sensor acquisition parameters in the TRAX. The payload should
contain the following:
AcquisitionMode:
This flag sets whether output will be presented in Continuous or Polled
Acquisition Mode. Polled Mode is TRUE and should be selected when the host
system will poll the TRAX for each data set. Continuous Mode is FALSE and
should be selected if the user will have the TRAX output data to the host system
at a relatively fixed rate. Continuous Mode is the default.
FlushFilter:
This is only relevant in Compass Mode. Setting this flag to TRUE results in the
FIR filter being flushed (cleared) after every measurement. The default is
FALSE.
Flushing the filter clears all tap values, thus purging old data. This can be useful
if a significant change in heading has occurred since the last reading, as the old
heading data would be in the filter. Once the taps are cleared, it is necessary to
fully repopulate the filter before data is output. For example, if 32 FIR taps is set,
32 new samples must be taken before a reading will be output. The length of the
delay before outputting data is directly correlated to the number of FIR taps.
PNIReserved:
These 4 bytes serve no function. PNI recommends populating the bytes with 0.
SampleDelay:
The SampleDelay is relevant when the Continuous Acquisition Mode is selected.
It is the time delay, in seconds, between completion of TRAX sending one set of
data and the start of sending the next data set. The default is 0 seconds, which
means TRAX will send new data as soon as the previous data set has been sent.
AcquisitionMode
UInt8
FlushFilter
UInt8
Payload
PNIReserved SampleDelay
Float32 Float32