Nortech PD27 Series - Page 9

307UM0200_01 May 2016 PD27x User Manual Page 9 of 30
3.2.7 Frequency (switch 2 and 1)
The frequency switches are used to shift the operang frequency of the detector. This is primarily used to handle
situaons in which more than one detector is used at the same site. The detectors must be set-up to ensure no crosstalk
(interference) occurs between adjacent loops connected to different detectors. This is achieved by ensuring that the
loops of the two detectors are spaced sufficiently apart (approximately 2 metres between adjacent edges) and also
ensuring that the detectors are set to different frequencies.
The loops connected to multichannel detectors are not suscepble to crosstalk due to the design of the loop interface.
Sw2 Sw1 Frequency
Right Right High Frequency
Le Right Medium High Frequency
Right Le Medium Low Frequency
Le Le Low Frequency
3.2.8 Sensitivity (switches 1 to 4)
The sensivity of the detector determines the change of inductance necessary to produce a detect. The PD27x provides
a selectable range of four sensivity sengs. Sensitivity is defined as a change in the inductance, with the PD27x it
ranges from 0.01% to 0.1%, with 0.01% being the highest sensivity selecon.
Sw4 Sw3 Sensivity Channel 1
Right Right (0.01%) - High Sensitivity
Le Right (0.02%) - Medium High Sensitivity
Right Le (0.05%) - Medium Low Sensitivity
Le Le (0.10%) - Low Sensivity
Sw2 Sw1 Sensivity Channel 2
Right Right (0.01%) - High Sensitivity
Le Right (0.02%) - Medium High Sensitivity
Right Le (0.05%) - Medium Low Sensitivity
Le Le (0.10%) - Low Sensivity
3.2.9 Push button (Retune and Powerfail)
The push button can be used to iniate a retune or to switch Powerfail on or o depending on how long the push buon
is held in.
Switch Descripon Hold Funcon
Push
button
Reset 3 sec This would iniate a detector retune
Power fail
status
10 sec
Hold for 10s to determine the state of Powerfail. If the LEDs
are ON, Powerfail is ON. If the LEDs are OFF, Powerfail is
OFF.
Power fail
toggle
30 sec
Holding for 30s will toggle the Powerfail status. The state of
Powerfail is known after holding for 10s. Aer 30s, if the
LEDs turn OFF, Powerfail is now OFF. If aer 30s the LEDs
turn ON, Powerfail is now ON.
The PD27x has a Powerfail funcon which is designed to retain the memory of a vehicle on the loop in the event of a
power fail situaon. This is designed specically for fail safe situaons to retain the output state and prevent a glitch
on the outputs in the event of a power failure.