Loop Installation
Status
4 Hz – 2 second
timing delay
1Hz - Shorted Loop
3/sec - Prior Loop Failure
A = Loop dimension parallel to the gate
B = Loop dimension perpendicular to the gate
C = Distance of the loop from the gate
Recommended Loop Wire: Reno LW-120 for 1/8" slots
Reno LW-116-S for 1/4" slots
THE WIRE IS
CONTINUOUSLY WOUND
IN THE LOOP SAW SLOT
FOR THE REQUIRED
NUMBER OF TURNS (2
turns shown)
REMOVE SHARP
INSIDE CORNERS
THE WIRES MUST BE
TWISTED TOGETHER
6 TWISTS PER FOOT
FROM THE END OF
THE SAW CUT TO
THE DETECTOR
BACKER ROD
1" piece spaced
about every
The vehic le detection ch aracteri stics of the i nductive loop detector ar e greatly in fluenced b y the loop size
and proximity to mo ving metal objects such as gates. Vehicles such as small motorcycles and hi gh-bed
trucks can be reliably detected if th e p rop er s i ze lo op i s s elec t ed . If th e lo op i s pla c ed too c los e to a m ovi n g
metal gate, the detector may detect the gate. The diagram below is intended as a reference for the
dimensions that will influence the detection characteristics.
General Rules
1. The detection height for a loop is 2/3rds the s hor te st le g ( A o r
B) of the loop. Example: Short leg = 6’ then Height = 4’ (2/3
x 6).
2. As leg A is made longer, distance C will need to increase.
Phoenix, AZ 85040 USA
Telephone: (480) 968-6407
Fax: (602) 437-1996
Website: www.editraffic.com
E-mail: contact@editraffic.com
OPERATING INSTRUCTIONS FOR
Model K Series
3. For reliable detection of small motorcycles, legs A and B
should not exceed 6 feet.
Loop Installation - Saw Cut Type
1 Mark the loop layout on the pavement. Remove sharp inside corners that can damage the loop wire insulation.
2 Set the saw to cut to a depth (typically 2" to 2.5") that insures a minimum of 1" from the top of the wire to pavement
surface. The saw cut width should be larger than the wire diameter to avoid damage to the wire insulation when placed in
the saw slot. Cut the loop and feeder slots. Remove all debris from the saw slot with compressed air. Check that the
bottom of the slot is smooth.
3 It is highly recommended that a continuous length of wire be used to form the loop and feeder to the detector. Loop wire
is typically 14, 16, 18, or 20 AWG with cross-linked polyethylene insulation. Use a wood stick or roller to insert the wire to
the bottom of the saw slot (do not use sharp objects). Wrap the wire in the loop saw slot until the desired number of turns
is reached. Each turn of wire must lay flat on top of the previous turn.
4 The wire must be twisted together a minimum of 6 twists per foot from the end of the saw slot to the detector.
5 The wire must be held firmly in the slot with 1" pieces of backer rod every 1 to 2 feet. This prevents the wire from floating
when the loop sealant is applied.
6 Apply the sealant. The sealant selected should have good adhering properties with similar contraction and expansion
characteristics to that of the pavement material.
1'
PC BOARD LOOP DETECTORS
I General
The Model K can be configured for 24 VAC or 120 VAC input power and Fail Safe or
Fail Secure mode of op er ation.
The model number designates the configuration as follows:
Model K-XXX-X
Blank or S. Blank = Fail Safe, S = Fail Secure.
24 or 120. 24 = 24 VAC input, 120 = 120 VAC input.
Please verify source vol tage before applying power.
II Indicators and Controls
1"
Flash N/A
Note: If the supply voltage drops below 75% of the nominal supply voltage, the
power LED will turn off, prov iding a visual check of low supply voltage. Model K
detectors operate with supply voltage as low as 70% of nominal supply voltage.
Sensitivity Level Rotary Switch
The 8-position rotary switch selects one of eight sensitivity levels as shown below.
Zero (0) is the lowest and seven (7) is the highest, with the normal (factory default)
being three (3). Use the lowest sensitivity setting that detects the desired vehicles.
Model K Operating Instructions 4 P/N 889-1100-00
DIP Switches
Switch
Medium
Relay B, Normally Open (N.O.)
Relay B, Normally Closed (N.C.)
Relay A Normally Closed (N.C.)
Relay A, Normally Open (N.O.)
See table under Frequency section
Presence/Pulse (DIP Switch 1)
Relay B has 2 modes of operation: Presence and Pulse. When in Pulse mode (DIP
switch 1 set to OFF), the 250 ms pulse can be set for entry pulse or exit pulse via DIP
switch 2. When in Presen ce mode, the presence hold time is the same as Output A.
Entry Pulse/Exit Pulse (DIP switch 2)
In Pulse Mode (with DIP s witch 1 set to OFF), the detector can be pro grammed to
output a 250 millisecond pulse only upon vehicle entry over the loop or only upon
vehicle exit from the loop. DIP switch 2 has no effect on output A (the presence
output).
FAULT Output (DIP switch 3)
Setting DIP Switch 3 to OFF enables the settings programmed via DIP switches 1 and
2 for Relay B. Setting the DIP switch to ON disables DIP switches 1 and 2 and forces
an output on Relay B on a loop failure. Factory default for DIP switch 3 is OFF.
Output Delay (DIP Sw itch 4)
A 2 second delay of outputs A and B can be activated by setting DIP switch 4 to the
ON position. Output delay is the time the detector output is delayed after a vehicle
first enters the lo op det ection area. If the 2 second Outpu t Delay featu re is activat ed,
the output relays will only be turned on after 2 seconds has passed with a vehicle
continuously present in the loo p detectio n area. If a vehi cle leaves t he loop d etection
area during the 2 second delay interval, detection is aborted and the next vehicle to
enter the loop detection area will initiate a new full 2 second delay interval. By
flashing the front panel DET LED at 4 Hz with a 50% duty cycle, the detector
indicates that a vehicle is being detected but th at the output is being delayed.
Sensitivity Boost (DIP Switch 5)
DIP switch 5 can be t urned ON to increase sensitivity only during the detect period
without changing the sensitivity of a vacant loop. When a vehicle enters the loop, the
detector will automatically boost the loop sensitivity during the detect condition. As
soon as no vehicle is detected, the detector immediately returns to the original
sensitivity level. This feature helps prevent dropouts during the passage of high-bed
vehicles and is particularly useful in sliding gate situations.
Limited Presence/True Presence (DIP switch 6)
Output A always a presence output. The detector has two presence hold time modes:
Limited Presence and True Presence. When set for True Presence (DIP switch 6
OFF), the detector will hold the output call for as long as a vehicle is present in the
loop detection area an d power is not removed or reset applied. True Presence ti me
applies only for normal size automobiles and trucks and for normal size loops (loop
area approx. 12 ft
2
to 120 ft2). When set for Limit ed Presence (DIP switch 6 ON) , th e
detector will typically hold the Call for about one to three hours when a vehicle is in
the detection zone.
Frequency (DIP switches 7 and 8)
Loop frequency is controlled by DIP switches 7 and 8. Sometimes where loops are in
close proximity, it is n ecessary to select a differen t frequency for each loop to avoid
loop interference – commonl y known as crosstalk. F our frequencies ar e available as
shown in the above table. Normal is the default frequency.
III Reset
Changing any DIP switch position (except 7 or 8) will reset the detector. After
changing the frequen cy selection switches, the d etector will require a reset (a reset
will clear the loop fault memory).
IV CALL Memory
When power is removed for 2 seconds or less, the detector automatically “remembers”
if a vehicle was present and a CALL was in effect. When power is restored, the
detector will continue to output a CALL until the vehicle leaves the loop. Power loss
or dips of 2 seconds or less will not bring a gate arm down onto cars as they wait at
the gate.
V Fuse (Automatic Recovery)
If 120VAC power is applied to the Model K-24, the automatic fuse will open. The
fuse will automatically reset when power is removed for three seconds. Check source
voltage before reinstalling.
VI Pin Connections
Note: All relay contacts shown above are wit h power applied, l oops connected, and
no vehicle present. Output B al ways operates in Fail Secure mode when loop or
power fails.
VII Warnings
Separately for each lo op, the lead -in should be a twisted pair created by twisting two
(2) loop wires all the way from the loop to the detector (including through all wiring
harnesses) at approximately six (6) full twists per foot. For trouble free operation, it s
highly recommended that all connections (including crimped connectors) be soldered.
2 3