VIII. Loop Installation:
The vehicle detection characteristics of the inductive loop detector are greatly influenced by the loop size and
proximity to moving metal objects such as gates. Vehicles such as small motorcycles and high-bed trucks can
be reliably detected if the proper size loop is selected. If the loop is placed too close to a moving 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:
SLIDE GATE
1. The detection height of a loop is 2/3 the shortest leg
(A or B) of the loop. Example: Short leg = 6 feet,
Detection Height = 4 feet.
A
2. As the length of leg A is increased, distance C must
also increase.
A = 6 ft 9 ft 12 ft 15 ft 18 ft 21 ft
C = 3 ft 4 ft 4.5 ft 5 ft 5.5 ft 6 ft
3. For reliable detection of small motorcycles, legs A
A = Loop dimension parallel to the gate
B = Loop dimension perpendicular to the gate
C = Distance of the loop from the gate
and B should not exceed 6 feet.
L o o p In st al la t i o n - S aw C ut T ype :
1 Mark the loop layout on the pavement.
2 Set the saw to cut to a depth (typically 2" to 2.5") that ensures a minimum of 1" from the top of the wire to pavement surface. The
saw cut w idth should be larger than the wire diameter to avoid damage t o the wire insulation when placed in the saw slot. Cut the
loop and feeder slots. .Remove sharp inside corners that can da mage the loop wire insulat ion. Remove all debris fro m 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 w ith cross-linked polyethylene insulation. Use a wood stick or roller to insert t he wire to the bottom of the
saw slot (do not use sharp objects). Wrap the w ire in the loop saw slot until the desired number of turns is r eached. 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 contraction and expansion c haracteristics similar
to those of the pavement material.
LOOP PERIMETER NUMBER OF TURNS
10 feet - 13 feet 5
14 feet - 26 feet 4
27 feet - 45 feet 3
46 feet – 80 feet 2
81 feet and up 1
1
1/8" to 1/4" SAW SLOT
THE WIRE IS
IN THE LOOP SAW SLOT
FOR THE REQUIRED
NUMBER OF TURNS (2
turns shown)
3
6
5
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
about every 1'
LOOP WIRE
3 TURNS
4
2
Operating Instructions
Model J Series
C
WITH S P1 O PTIO N - 5 00ms PUL S E O U TPUT
I. General:
Please verify source voltage before applying power. The model designation indicates the input power required,
B
connector type, and Fail-Safe / Fail-Secure configuration for the detector as follows.
Model J-xx-x-x-SP-1
Blank = Fail-Safe, S = Fail-Secure
M = Male Connector
F = Female Connector
E = European Connector
12 = 12 VDC
24 = 24 VDC
The detector is factory configured for either Fail-Safe or Fail-Secure operation (see unit label). The output state
of the output relay in either Fail-Safe or Fail-Secure mode is listed in the table below.
Relay Power Failure Loop Failure Power Failure Loop Failure
A
B
II. Indicators and Controls
i. Power / Detect / Fail LEDs:
The detector has one green and two red LED indicators that are used t o provide an indication of the
detector’s power status, output state, and/or loop failure conditions. The table below lists the various
indications and their meanings.
Status PWR (Power) LED DET (Detect) LED FAIL LED
Off
On
MIN
1"
Flash
Note: If the supply voltage drops below 75% of the nominal supply voltage, the power LED will turn off,
providing a visual check of low supply voltage. Model J detectors will operate with supply voltage as low
as 70% of nominal supply voltage.
ii. Rotary Switch (Sensitivi ty):
The eight-position rotary switch selects one of eight (8) sensiti vity levels as shown in the table
below. 0 is lowest and 7 is highest, with normal (factory default) being 3. Use the lowest sensitivity
setting that will consistently detect the smallest vehicle that must be detected. Do not use a sensitivity level
higher than necessary.
Position 0 1 2 3 * 4 5 6 7
-∆∆∆∆L/L
* Factory default setting.
PC BO ARD L OOP DETE C T ORS
Fail-Safe Fail-Secure
Call Call No Call No Call
No Call No Call No Call No Call
No power or low power No vehicle present Loop OK
Normal power to detector Vehicle present Open Loop
N/A 4 Hz - 2 second timing delay
1.28% 0.64% 0.32% 0.16% * 0.08% 0.04% 0.02% 0.01%
1 Hz – Shorted Loop
3 Hz - Prior Loop Failure
Recommended Loop Wire: Reno LW-120 for 1/8" slots
Reno LW-116-S for 1/4" slots
P/N 889-1002-00 Rev: June 2020 4 Model J Operating Instructions
iii DIP Switches:
Switch ON OFF Factory Default
1
2
3
4
5
6
7
8
Presence Mode B Relay Pulse Mode B Relay Off
Exit Pulse B Relay Entry Pulse B Relay Off
Fault Output B Relay
(Overrides Switches 1 & 2)
Two Second Delay No Delay Off
Sensitivity Boost No Boost Off
Limited Presence True PresenceTM Off
(See Table under Frequency Section)
Presence / Pulse B Relay Off
Frequency
On
Off
Relay B Output Mode (DIP Switches 1 and 2):
Relay B has four (4) modes of operation: Pulse-on-Entry, Pulse-on-Exit, Presence, and Fault. Fault mode
is selected with DIP switch 3. (See the Relay B Fault Output section b elow for detai ls.) DIP switches 1
and 2 are used to configure the Presence and/or Pulse output modes of Relay B.
When set to operate in Pulse mode (DIP switch 1 set to OFF), Relay B can be set to provide a 500
millisecond pulse when a vehicle enters or exits the loop detection zone. DIP switch 2 is used to select
Pulse-on-Entry or Pulse-on-Exit. When DIP switch 2 is OFF, Pulse-on-Entry is selected. When DIP
switch 2 is ON, Pulse-on-Exit is selected.
When set to operate in Presence mode (DIP switch 1 set to ON), Output B presence hold time is the same
as Output A.
The table below shows the various combinations of switch settings and Relay B modes of operation.
Switch Pulse-on-Entry * Pulse-on-Exit Presence Presence
1
2
* Factory default setting.
OFF * OFF ON ON
OFF * ON OFF ON
Relay B Fault O utput (DIP Switch 3):
When DIP switch 3 is in the ON position, Output B will operate in Fault mode. When operating in Fault
mode, Relay B will provide a fault indication only when a loop fault condition exists. If a loss of power
occurs, Relay B will operate as a Fail-Secure output. If the loop fault condition self-corrects, Relay B will
resume operation in the No Fault output state. The factory default setting is OFF (Relay B Presence or
Pulse).
NOTE: Setting this switch to the ON position overrides the settings of DIP switches 1 and 2.
Output Delay (DIP Switch 4):
A two 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 outputs are delayed after a vehicle first enters the loop detection zone.
If the two second Output Delay feature is activated, the output relays will only be turned on after two
seconds have passed with a vehicle continuously present in the loop detection zone. If the vehicle leaves
the loop detection zone during the two second delay interval, detection is aborted and the next vehicle to
enter the loop detection zone will initiate a new full two second delay interval. The detector provides an
indication that a vehicle is being detected but that the outputs are being delayed, by flashing the front panel
DET LED at a four Hz rate with a 50% duty cycle. The factory default setting is OFF (no Output Delay).
Sensi tivity Boost (DIP Switch 5):
DIP switch 5 can be turned ON to increase sensitivity during the detect period without changing the
sensitivity during the no detect period. The boost feature has the effect of temporarily increasing the
sensitivity setting by up to two levels. When a vehicle enters the loop detection zone, the detector
automatically boosts the sensitivity level. As soon as no vehicle is detected, the detector immediately
returns to the original sensitivity level. This feature is particularly useful in preventing dropouts during the
passage of high bed vehicles. The factory default setting is OFF (no Sensitivity Boost).
Presence Hold Time (DIP Switc h 6):
Output A always functions as a presence output. DIP switch 6 can be used to select one of two presence
hold times; Limited Presence or True Presenc eTM. Both modes provide a Call output when a vehicle is
present in the loop detection zone. True PresenceTM is selected when DIP switch 6 is OFF. If DIP
switch 6 is ON, Limited Presence is selected. Limited Presence will typically hold the Call output for
about one to three hours. True PresenceTM will hold the Call as long as the vehicle is present in the loop
detection zone provided that power is not interrupted or the detector is not reset. TruePresenceTM time
applies only for normal size automobiles and trucks and for normal size loops (approximately 12 ft
ft2). The factory default setting is OFF (True PresenceTM Mode).
Frequency (DIP Switches 7 and 8):
In situations where loop geometry forces loops to be located in close proximity to one another, it may be
necessary to select different frequencies for each loop to avoid loop interference, commonly known as
crosstalk. DIP switches 7 and 8 can be used to configure the detector to operate at one of four frequencies
corresponding to Low, Medium / Low, Medium / High, and High as shown in the table below.
NOTE: After changing any frequency switch setting(s), the detector must be reset by momentarily
changing one of the other switch positions or by momentarily changing the sensitivity setting.
Switch
7
8
* Factory default setting.
Low (0) Medium / Low (1) * Medium / High (2) High (3)
ON ON * OFF OFF
ON OFF * ON OFF
Frequency
III. Reset:
Changing any DIP switch position (except 7 or 8) or the Sensitivity level setting will reset the detector. After
changing the frequency selection switches, the detector must be reset.
IV. Call Memory:
When power is removed for two 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 detection zone (loss of power or power dips of two seconds or less will not bring a gate arm
down onto cars as they wait at the gate).
V. Failed Loop Diagnostics:
The FAIL LED indicates whether or not the loop is currently within tolerance. If the loop is out of tolerance,
the FAIL LED indicates whether the loop is shorted (one Hz flash rate) or open (steady ON). If and when the
loop returns to within tolerance, the FAIL LED will flash at a three flashes per second rate to indicate that an
intermittent loop fault has occurred and has been corrected. This flash rate will continue until another loop fault
occurs, the detector is reset, or power to the detector is interrupted.
VI. Pin Connections:
Female
Connector Pin
1 10 10
2 9 9
3 8 8
4 7 7
5 6 6
6 5 5
7 4 4
8 3 3
9 2 2
10 1 1
Notes: All pin connections listed above are with power applied, loop(s) connected, and no vehicle detected.
A detector reset occurs when Pin 5 is connected to Pin 3 on the Female connector or when Pin 6 is
connected to Pin 8 on the Male or Euro connector.
Male
Connector Pin
Euro
Connector Pin
Function
Loop
Loop
DC Common
DC +
Reset
Relay B, Normally Open (N.O.)
Relay B, Common
Relay A, Normally Open (N.O.)
Relay A, Normally Closed (N.C.)
Relay A, Common
VII. Warnings:
Separately for each loop, 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 is highly recommended that all connections (including crimped connectors)
be soldered.
2
to 120
2
3