GTT Canoga C924 Series, Руководство по установке, Страница: 38 / 81

Canoga™ Vehicle Detectors
Canoga™ C924X Series Installation Manual
32 – Vehicle Detector Setup & Configuration
Table 5-3 Sensitivity Setting Values
Sensitivity Detect Threshold Desirability
C 1024 nH Rarely Appropriate
1 512 nH Seldom Appropriate
2 256 nH
3 128 nH
4 64 nH
5 32 nH Unusual Situations Only
6 16 nH Unusual Situations Only
7 8 nH Not Recommended
Whenever the sensitivity is changed on channels attached to Microloops, the Threshold
Multiplier and Slope divisor for those channels must also be changed. The values offered by the
Suggest button are valid only for “typical single probe installations”. Set these parameters as
follows:
Threshold Multiplier:
∆
L of typical auto/(2*Sensitivity in nanohenries) < setting <
∆
L of typical
auto/Sensitivity in nanohenries
Slope Timer: = 0.15 sec.
Slope Divisor: = Sensitivity in nanohenries/32 (use a divisor of 64 if channel noise peak-to-peak
is greater ½ sensitivity threshold)
Bridge Time: = minimum typical gap between vehicles (time between vehicles, typically 0.3
sec. to 0.5 sec. are common values)
(Threshold Multiplier)*(Sensitivity Threshold) represents a definition of signal magnitude caused
by auto presence. (3)*(Slope Timer) is set to less than typical minimum vehicle gap.
(Sensitivity Threshold)/(Slope Divisor) represents a definition of signal size that is greater than
noise when no vehicle is present.
3. Complete the operation of setting the Sensitivity and Microloop mode parameters by clicking
the Apply button when no vehicles are over the Microloop sensors or loops attached to the
vehicle detector. Clicking OK will not send the settings to the vehicle detector. OK will only
close the Settings window.