exemys ID Series, Руководство пользователя

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IDx User´s Manual Exemys
8.2 Permanent while present
The output signal activates when the vehicle enters the loop and remains on while the vehicle
crosses the loop.
Vehicle over the loop
OUTPUT
LED
Figure 4 - Output signal permanent while present
Presence Time (PRES)
Regardless of the output signal type (pulsed or permanent while present), if a vehicle remains
over the loop longer than a certain amount of time, the IDx will reset, causing a re-tuning. This
period of time, called
presence time
, depends on the size of the metallic mass that’s being
detected. A car will reset the IDx after remaining over the loop for approximately an hour.
Frequency (FREC)
You can choose the working frequency of both channels to avoid interference with other
detection systems. Frequencies differ from each other around 5%.
The frequency will depend on the loop’s geometry. The detector works with frequencies from
25Khz to 120KHz. Above or below those frequencies the detector will indicate failure. To avoid
interference between the IDx’s channels, detection on each channel is done separately. When
detection is taking place in one channel the other one is off, this way mutual interference is not
possible. The IDx switches from one channel to the other with enough speed as not to affect
normal operation.
Loop construction and installation
The wire used for the loop must reach the detector module without cuts. The ends of the wire are
brought back to the enclosure. This sector of wire must be twisted, at least 25 turns per meter ( 8
per feet), and it can’t exceed 100m (330 feet). If the cut in pavement is shared by the channels,
increasing the number of turns per meter and using shield wires is recommended (shield must be
ground connected in detection module).
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