Polhemus 3SPACE FASTRAK, Руководство пользователя, Страница: 38 / 124

FASTRAK MANUAL
Rev. G 33 JUNE 2012
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Data Format (binary is more efficient than ASCII)
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Filtering
The FASTRAK baud rate should be set to the highest setting that is compatible with the host
computer and the communication software. Although the FASTRAK system runs at 120 Hz, it
may appear that it is running slower if the output is constrained by a slow baud rate. The
FASTRAK is capable of running at speeds of up to 115,200 as selected by the I/O Select
Switches on the back panel or as selected by the software command ‘o’ (see
‘o’ – Set Output
Port on page 62 for full description). Of course, the USB interface can be utilized without
concern for these limitations.
The FASTRAK default output record contains measurements for X, Y, Z in inches and Azimuth,
Elevation, and Roll in degrees. This output format can be easily modified by using
‘O’ – Output
Data List on page 57 . Although the FASTRAK offers a variety of output selections, it is best to
keep the output record length constrained only to the data that is needed. Excessive data in the
output record can slow down the transmission and not allow the system to output data to the host
at the maximum update rate.
The FASTRAK contains an adaptive filter that is designed to control noise in the data output.
The filter can be applied to Position or Orientation or both and can be activated with “simple”
commands that select “low”, “medium”, or “heavy” filtering. It should be noted that the effect
that is seen in the data may have or appear to have a slower dynamic response with medium or
heavy filtering selected.