Wavetronix SmartSensor Advance Extended Range (SS-200E) - User Guide - Manual (Page 78)

CHAPTER 7 • CHANNELS-ALERTS-ZONES 77
Figure 7.7 – Providing Dilemma Zone Protection
By providing zones for level-one priority dilemma zone protection, level-two dilemma zone
protection and queue clearance, a priority channel provides exceptional detection from
start-of-green to end-of-green.
Note
There may be a number of uses of the discovery range feature for other applications
than truck priority. For example, you could require that a vehicle be discovered at a
certain range (using the discovery range threshold) and that it travels to a down-
stream zone several hundred feet away before it activates a channel output. This is
a way to know that we have tracked a specific vehicle over an extended range. This is
better than simple using the channel delay because it isolates a single vehicle.
Pulse Channel
A pulse channel consists of one dedicated zone. When a tracked detection enters the zone,
the channel will pulse on once and then return to the off state. The on time and the mini-
mum off time of the pulse are predetermined. If two detections enter the zone at exactly the
same time, then the associated pulses will be sent sequentially with the minimum off time
separating them.
Note
The duration of the on time and off time in each pulse is controlled by the output
frequency setting in SSMA. By default the output frequency setting is 130 ms. Since
standard traffic controllers sample at 10Hz, a 130 ms on time and off time should be
of sufficient length to faithfully transfer all pulses generated by the sensor.