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North reference, Endianess, Filter setting (taps) – PNI CompassPoint Prime User Manual

Page 19: Acquisition settings

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Prime User Manual r08

Page 13

5.3.2

North Reference

Magnetic

When the button is selected, heading will be relative to magnetic north.

True

When the button is selected, heading will be relative to geographic (true)

north. In this case, the declination needs to be set in the “Declination” box. Refer to

Section 6.3 for more information.

5.3.3

Endianess

Select either the or Endian button. The default is . See Section 7.2

for more information on appropriate data formats.

5.3.4

Filter Setting (Taps)

The Prime incorporates a finite impulse response (FIR) filter to effectively provide a

more stable heading reading. The number of taps represents the number of measurement

readings to be included in the filter. The user should select either 0, 4, 8, 16, or 32 taps,

with zero taps representing no filtering. The default setting is 8 taps.

The Prime is configured to update the filter with each new measurement reading. When a

new reading is added to the filter, the oldest reading in the filter is dropped. For example

if 8 taps is selected, the 8 most recent readings will populate the filter.

Note: Selecting a large number of taps will significantly slow the time for the initial heading
reading, since the filter must be fully populated before the Prime will output a heading reading.

5.3.5

Acquisition Settings

Mode

“Poll” mode should be selected when the host system will poll the Prime for data.
StudioPrime allows the user to simulate this on their PC. In this case, StudioPrime

requests data from the Prime module at a relatively fixed basis.

“Push” mode should be selected if the user will have the Prime output data at a
relatively fixed rate to the host system. In this case the Prime module is pushing data

out to StudioPrime at a relatively fixed rate.

Poll Delay

The Poll Delay is relevant when Poll Mode is selected, and is the time delay, in

seconds, between the completion of StudioPrime receiving one set of sampled data

and requesting the next sample set. If the time is set to “0” then StudioPrime requests