TDT RZ2 Manual page 631

System 3
on all devices. The iterate function duplicates the construct 16 times, with an input
signal from channel 'x' scaled by 114.35 and then sent to a hop out.
Iterate: x =1 to 16 by 1
dc
Ch={x}
.,1-01...]
The next circuit segment scales each channel based on the table above for the FOB
motion tracker. The first three channels in this example scale Azimuth, Elevation, and
Roll. If the input to the HTI3 includes two motion tracker channels, then channels 7,
8 and 9 will contain the Azimuth, Elevation, and Roll information for the second
motion tracker. To return this information in radians, the scale factor should be
changed to 3.14159. Channels 4-6 are scaled to inches. To scale the XYZ
coordinate space to centimeters the scale factor would be 91.44. This circuit can be
easily modified to use with the FT motion tracker by inserting the appropriate scale
factors from the table above.
chan1
chan2
chan3
Data Storage and Visualization of Signal Input
Motion tracker signals are updated/transferred to the HTI3 at rates up to 120Hz. The
HTI3 sends signals to the RX/RP device at sample rates up to 25 kHz.
means that each value from the motion tracker may be repeated on the DSP up to
200 times. To minimize the redundancy of the signal, the channel outputs can be
decimated by a fixed value. This will decrease the amount of data stored on either
the DSP or transferred to a computer. The construct below shows two ways to
decimate the signal. One way shows real-time visualization of the signal and the
other illustrates storage of the signal to disk.
Since the following circuit segments are based on the data transfer rate of the
motion tracker itself, users should review the documentation provided with their device
before using the parameter values shown.
[1...,2-01...]
ScaleAdd
SF=114.35
Shft=0
[1:2,0]
ScaleAdd
Azm1_Deg
SF=180
Shft=0
[1:4,0]
ScaleAdd
Elv 1_Deg
SF=180
Shft=0
[1:6,0]
ScaleAdd
Roll1_Deg
SF=180
Shft=0
chan{x}
[1:8,0]
ScaleAdd
chan4
SF=36
Shft=0
[1:10,0]
ScaleAdd
chan5
SF=36
Shft=0
[1:12,0]
ScaleAdd
chan6
SF=36
Shft=0
HTI3 Head Tracker Interface
17-13
X1_in
Y1_in
Z1_in
This