
FASTRAK MANUAL
Rev. G
31
JUNE 2012
Select the “Request Data” button to get data from the FASTRAK over the USB port.
Receiving data from the FASTRAK using the GUI confirms that the USB device drivers have
been successfully installed on the host computer and the FASTRAK should now be able to
communicate with the host application over the USB port. For subsequent utilization of the USB
I/O, simply make sure that the USB communication cable is connected to the FASTRAK and the
host computer, before turning on the FASTRAK power.
To return to RS-232 communication, disconnect the USB cable and cycle the power on the
FASTRAK system. (Make sure the RS-232 cable is connected and that the host communication
software settings are set correctly, i.e. com port selection, baud rate, parity, etc.)
8.6 Synchronization
Synchronization defines and controls the precise time that a FASTRAK system measurement
cycle will start and thereby controls the tracking output from an application system point of
view. The FASTRAK system has three distinct synchronization modes that are controlled by the
‘y’ – Set Synchronization Mode
) and are defined as:
Command
Synchronization Mode
y0<>
Internal Sync. (Default)
y1<>
External Sync.
y2<>
Video Sync.
8.7 Internal Sync
In the Internal Sync mode, each measurement cycle of the FASTRAK system starts immediately
after the previous cycle ends. The system update rate is slightly greater than 120 Hz, and cycle-
to-cycle variations on the order of microseconds are possible in this mode. Only the ‘y0’
command is required to initiate the Internal Sync mode and no input is required for the system’s
SYNC IN port.
8.8 External Sync
The External Sync mode allows the user to define when the FASTRAK system measurement
cycle will start, by means of a user supplied external sync pulse. This mode may be used to
synchronize other peripheral instrumentation to the FASTRAK data collection cycle or to slow
the FASTRAK to a known and desired rate. To initiate the External Sync mode an external