User's Manual

306UM0002 - 01 TD236 Enhanced Detector User Manual Page 10 of 35
Channel1 Channel 2
S6 S5 S4 S3
Off Off Off Off High
On Off On Off Medium-High
Off On Off On Medium-Low
On On On On Low
3.2.3 Presence Time
The presence time is a mode, which allows the detector to have a presence time of no longer than
the time set by the switch settings. There are four presence time selections available and can be
selected by using switches numbered 7 and 8 on the front of the enclosure as follows: -
S8 S7
Off Off ∞ no fixed time
On Off 40 minutes
Off On 4 minutes
On On 1 Second
The presence time as shown above, may be altered according to the requirements.
The 1 second presence time setting will give a pulse on detection of a vehicle with a duration of 1
second. The detector will immediately re-adjust to the normal operating point and will give another
detect in the event of a further change in the loop inductance. The detector may be used as a
passage detector in this mode.
The 4 minute and 40 minute presence time settings work in the same way as the 1 second setting,
however the detector will now give outputs of 4 minutes or 40 minutes. If the vehicle which caused
the inductance change moves off the loop within the selected time period, then the detector will go
out of detect and the presence time will be reset to zero for the next detect cycle. The detector may
undetect before the expired time period if the change in inductance for the vehicle is small
The “no fixed time-out” setting does not have a fixed time period and the presence time is
dependant on the magnitude of the inductance change caused by the vehicle over the loop.
On times longer than 1 second there will be a “paralysis time” of approximately 4 seconds between
actuations.
3.2.4 Pulse / Presence
The channel’s relay may be set to either Pulse Mode or Presence Mode with switches No. 9 & No.
10 as shown in the table below: -
Channel1 Channel 2
S10 S9
Off Off Presence
On On Pulse
3.2.5 Reset Switch
The detector automatically tunes to the inductive loops connected to it when power is applied,
whether on initial installation or after any interruption in the power supply. Should it be necessary to
retune the detector, as may be required after the changing of any switch selections or after moving
the detector from one installation to another, momentary operation of the RESET switch will initiate
the automatic tuning cycle. Tuning should take approximately 5 seconds