DSP222H_Manual_A
Page 15 of 17
Front Panel Controls:
Front panel mounted DIP switches allow the user to select sensitivity, pulse/presence
and frequency on each channel.
Operational Modes:
Pulse - 125 ms ±25 ms momentary output
Presence Time - Meets or exceeds the State of California (Caltrans) Specifications.
(Minimum presence = 10 minutes for a change of inductance of 0.06% and minimum
presence = 3 minutes for a change of inductance of 0.02%)
Note: When operating in the pulse mode, a vehicle remaining over a loop will inhibit
further pulse outputs from being issued for a period of 2 seconds after which time
vehicles passing over the loop will again be detected.
Sensitivity:
One of seven settings may be selected to optimize detection on varying loop and lead-in
configurations. Sensitivity is defined as the minimum percentage change in
∆
L/L of the
total inductance (loop plus lead-in). Selecting level 0 will switch the channel off. In this
condition, the loop oscillator is de-energized, and the output will remain in the no call
state.
Sensitivity
∆
L%
Response Time (ms)
0
Off
Off
1
.64
.5
2
.32
1
3
.16
2
4
.08
4
5
,04
8
6
.02
16
7
.01
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