FASTRAK MANUAL
Rev. G
32
JUNE 2012
must be input to the SYNC IN port and the
‘y1’ command issued.
8.9 Video Sync
The Video Sync mode should be used when a receiver will be operating in close proximity to a
CRT monitor and the FASTRAK measurements appear noisy. (The amount of noise detected
will ultimately determine the definition of “close proximity,” but it is usually when the receiver
is less than 24 inches away from the monitor.) The reason this can occur is that all CRT monitors
produce a magnetic field during the vertical refresh cycle. After connecting the video sync
detector and sending the ‘y2’ command, the detector will sense the magnetic field and cause the
FASTRAK to begin each measurement cycle after a slight pause for settling time. This ensures
that the FASTRAK measurement cycle will not occur during the monitor refresh cycle and
eliminate noisy data.
8.10 Multiple Systems Operation – FASTRAKS produced as of
January 2012
When using more than one FASTRAK in the same area, it is important to ensure that each unit
have a different Frequency Select Module.
NOTE: Separation distance is defined as the distance between the transmitter of one
system and the receiver of another system when both systems are operating.
Without changing the frequency module, the minimum separation distance is 23 feet or 7 meters.
If the Frequency Select Modules are different, then the minimum separation distance is 15 inches
or 38 centimeters. Clearly, the latter option offers the greatest set up flexibility and user freedom.
The separation distance guidelines are restated below for further clarification:
If systems have
identical Frequency Select Modules
:
•
Separation distance should be 23 feet or 7 meters
If systems have
different Frequency Select Modules
:
•
Separation distance should be 15 inches or 38 centimeters, with transmitter-to-transmitter
adjacent spacing no closer than 6 inches or 15.2 centimeters
Again, separation distance is defined as the distance between the transmitter of one system and
the receiver of another system.
NOTE:
These separation distances assume FASTRAK systems
using standard 2-inch transmitters and standard receivers.
8.11 Output Considerations
Most applications of the FASTRAK system involve using its data output to manipulate some
type of computer graphics in real time. In this condition, it is extremely important to allow the
data to be utilized as quickly as possible and to avoid latency or lag. Lag is defined as the
interval of time between requesting a tracker data point and receiving it into the host computer.
Factors that could increase this lag are:
•
Baud Rate
•
Output Record Length