304UM0001 Rev 00
PD160 Enhanced Series User Manual
Page: 19 of 39
3.3 Front Panel Indicator
The front panel indicators consist of a Red Power / Status LED and a Green Channel LED.
There are four possible conditions which are indicated by the LED’s.
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Idle condition – no vehicle is detected
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Detect condition – a vehicle is detected passing over the inductive loop
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Tuning condition – the detector is currently tuning to the loop
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Fault condition – the detector is unable to tune to the loop as it is either out of operational
conditions such as low signal strength or frequency out of range, or there exists a fault on the loop
such as a short circuit or an open circuit.
If a loop fault exists, the Green Channel LED will come on and flash at a rate of 2Hz indicating the
fault. If the fault is self-healing the detector will continue to operate but the LED will flash at a slower
rate of 1Hz indicating to the user that a fault has occurred. The detector must be power cycled or have
the statistics cleared in order to clear the historical fault information.
In order to distinguish between a detect condition and a tuning condition, the Channel LED displays
the same in tuning as it does in fault.
Once the channel is tuned, the Green Channel LED will go off. As indicated above, if the unit has
recovered from a fault, the channel LED will flash at 1Hz, otherwise it will remain off.
In the event of a vehicle being detected passing over the inductive loop, the Green Channel LED will
light up indicating the presence of a vehicle and remain on for the duration of the detected vehicle.
It should be noted, however, that the Channel LED does NOT necessarily represent the output state of
the relays. It only represents the detection of a vehicle over the loop. The relay state could for example
be different from the LED state in the case of a pulse output after its pulse duration, a fault output, or a
delayed (filtered) output. The only time the Channel LED will go off while a vehicle is still present is if a
presence time is set and has expired or if the channel is in limited presence mode and has expired.
The Red Power LED indicates that the unit is powered and functional. In the event of a fault recovery,
the Red Power LED will flash at the rate of 1Hz, out of sync with the channel LED, to indicate that the
channel has recovered from a fault. This is to provide visibility if the channel is in detect at the time of
viewing.
