Wavetronix SmartSensor V User Manual page 53

CHAPTER 5 • SENSOR SETTINGS
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Interval Data – Allows you to specify the length of your intervals as well as how those
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intervals are stored. The interval refers to the time (in seconds) that traffic data is ag-
gregated (minimum interval is five seconds). Interval data is stored directly into the
sensor's SRAM memory, which is volatile and will not persist after a power cycle. The
number of intervals is limited to 246. You can also tell the sensor to move the data from
SRAM to the sensor's flash memory by clicking the Store in Flash Memory check box.
This protects the data because flash memory persists after power cycles. The capacity
in flash is about ten times greater than SRAM. If the Store in Flash Memory box is not
checked, the interval data will remain in SRAM until it is overwritten. Flash storage
management features are explained in greater depth in the Data Collection Setup sec-
tion of chapter 7.
Vehicle Classification – Lets you customize vehicle classifications by length. Enter the
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maximum length amounts for small and medium class vehicles in the active text boxes
and SmartSensor Manager will automatically determine the minimum lengths.
Lane Setup – Allows you to change specific lane information such as lane name and
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direction of travel, for your own information and for identification.
You can also change scale occupancy (loop size) and scale speed (loop spacing). The
entry in these columns for each lane represents the manual scaling applied to the oc-
cupancy/duration and speed data. The occupancy scale factor is the ratio of each lane's
loop size to the default loop size. The speed scale factor is the ratio of each lane's loop
spacing to that of the default loop spacing. You can modify the scale factors by clicking
on the arrows to the right of each box.
Unlike the SmartSensor HD, it is often necessary to calibrate the SmartSensor V for
vehicle length classification and occupancy measurements. This calibration should be
done on a site-by-site basis and is dependent upon detection thresholds.
The following table provides some generic guidance on scale factor values. In general,
lanes further away should have a lower scale factor. Also, a SmartSensor V will tend to
have lower scale factors then a SmartSensor 105 at the same location. Below are some
example values for lane centers every 10 feet:
Figure 5.4 – Data Collection Tab