Wavetronix Click 500 (programmable controller) (CLK-500) - User Guide - Manual (Page 90)

CHAPTER 9 • CLICK 512 89
second delay is fixed.
4 Output is activated.
5 Output is deactivated at the end of the duration.
6 Front-edge of vehicle reaches the sign (assuming constant speed).
Note
You can have a maximum of five vehicles concurrently being monitored from steps
3 to step 4. If you have extremely high traffic flow conditions where multiple over-
speed/over-length vehicles are possible, consider dedicating a single output to each
lane to prevent dropping detections.
Note
The 35-byte serial communication delay from the sensor to the Click 512 is 3 ms at
115.2 kbps. The 9-byte serial communication delay from the Click 512 to the Click
104/112/114 is 2 ms. This is a total of 0.005 seconds of additional delay (not depicted
in preceding graph). At 9600 bps, this increases to up to 0.038 seconds of additional
delay.
The second method, the point trigger method, also provides a certain level of uniformity, in
that the warning sign is activated when vehicles reach a certain point. However, the warning
sign will deactivate at different points since the duration is a predetermined fixed period of
time. This method can require a setback distance of 300 (or more) feet between the location
of the SmartSensor HD and the warning sign.
In order to trigger at a point upstream of a sign:
1 Select the Automatic (English) configuration options.
2 Specify the corresponding setback distance in feet. In this case, the setback distance is
from the location of the SmartSensor HD unit to the selected trigger point (upstream
of the warning sign).
3 Specify the duration in milliseconds.
The following diagram illustrates the basic timing of this option as a series of 5 steps. Some
portions of the timing are variable and others are fixed.