DoorKing 9409 Dual Channel, Информационное руководство

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Loop Info-Q-2-16 7
Loop Detector Cross-Talk and False Calls
The actual loop operating frequency (in KHz) is a function of the frequency DIP-switches on the loop
detector. A common problem with loops are when they are positioned too close to each other and
their detection fields overlap. If the loops are on similar frequencies, this can cause “cross-talk”
between the loops and “false calls” can occur in the loop detector. Changing the frequency of
one
loop (switching it’s frequency as far away from the other loop’s frequency as possible) will eliminate
the “false calls”. Switching the frequency of a loop
WILL NOT affect the loop’s detection height.
Detection Field Around Loops
It is important that the loops are installed far enough away from all moving metal
objects (gate) to keep the loop’s detection fields clear. The 1/2 to 2/3 the length
of the short leg of the loop will determine a detection field limit. Do not install the
loop closer to the gate than the short leg of the loop otherwise the movement of
the gate will interfere with the loop’s detection field and the loop detector will
give a “false call” and reverse the gate’s direction in mid-cycle.
A simplified
solution is to place loops AT LEAST 4 feet away from each other or the gate.
Frequency
DIP-switches
9410
L1
Reverse
Loop
Short Leg
Length
1/2 to 2/3rd Short Leg Length Detection Field
1/2 to 2/3rd Short Leg Length Detection Field
When loop detection fields do not overlap,
loop detectors can be on similar frequencies.
When loop detection fields overlap, loop detectors MUST be on
different frequencies or they will “cross-talk”. (See below)
Reverse
Loop
Slide Gate
Swing Gate
Loop Detection Field Interference and Loop Placement
Reverse
Loop
Short Leg
Length
Reverse
Loop
Shadow Loop
See page 12 for
more information.
Optional
Automatic
Exit Loop
Optional
Automatic
Exit Loop
Short Leg
Distance
Short Leg
Distance
Short Leg
Distance
or 4 ft Min.
from Gate
Drawings not to scale
or 4 ft Min.
from Gate
Loop Detection Field
Loop Detection Field Loop Detection Field
Loop Detection Field
or 4 ft Min.
from Gate