Model T-110
Loop Detector
Operations Manual
Single Cha nnel DIP Switc h Programmab le Inductive Loop Vehicle
Detector
This manual contains technical in formation for the
Model T-110 Loop Detector
pn 889-2008-01 Revision: April 2020
THE FOLLOWING PRODUCT WAS DESIGNED, INSPECTED , TESTED AND
MANUFACTURED IN THE USA BY EBERLE DESIGN, INC. IN PHOENIX, ARIZONA.
INFORMATION CONTAINED HEREIN IS PROPR IETARY TECHNICAL INFORMATION OF
EBERLE DESIGN, INC. PUBLICATION, REPRODUCTION OR USE IN WHOLE OR PART IS
NOT PERMITTED EXCEPT UNDER TERMS AGREED UPON IN WRITING. ALL
REGISTERED TRADEMARKS OF EBERLE DESIGN INC. ARE UNDER
IT IS AN EBERLE DESIGN, INC. RECOMMENDATION THAT EACH UNIT BE TESTED
AT LEAST ANNUALLY TO ENSURE COMPLIANCE WITH FACTO RY
SPECIFICATIONS AND MEETS PROPER OPERATIONAL STANDARDS. THE
RESULTS OF THIS TESTING WILL BE DOCU MEN TED.
© COPYRIGHT
MAINTENANCE NOTE
Model T-110 Operations Manual
Table of Contents
Section 1 General Description .......................................................................................................... 1
Section 2 General Characteristics .................................................................................................... 2
2.1 Loop Frequency ..................................................................................................................... 2
2.2 Presence / Pulse Mode ........................................................................................................... 2
2.3 Sensitivity .............................................................................................................................. 2
2.4 Call Exte ns ion ........................................................................................................................ 2
2.5 Call Delay .............................................................................................................................. 2
2.6 Audbi le D etect Signal ............................................................................................................ 2
2.7 Test Mode .............................................................................................................................. 3
Section 3 Specifications ..................................................................................................................... 3
3.1 Physical .................................................................................................................................. 4
3.2 Electrical ................................................................................................................................ 4
3.3 Operational ............................................................................................................................ 4
3.4 Table: Sensitivity, -∆L/L, and Typical Response Time .......................................................... 4
3.5 Table: Default Settings (Front PanelMounted DIP Switch) ................................................... 6
3.6 Table: Pin Assignments ......................................................................................................... 6
Section 4 User Interface .................................................................................................................... 6
Section 5 Installation and Set-Up ..................................................................................................... 8
5.1 Front Panel Programming DIP Switches ................................................................................ 8
5.2 Front Panel Delay and Extension Timing DIP Switches ........................................................ 9
5.3 Front Panel Mounted Pushbutton – Audible Detect Signal (Buzzer).................................... 11
5.4 Front Panel Mounted Pushbutton – Detector Reset .............................................................. 11
5.5 PC Board Mounted Jumper – Test Mode ............................................................................. 11
5.6 Loop Fail Indications ........................................................................................................... 11
5.7 Resetting the Detector .......................................................................................................... 12
Section 6 Block Diagram ................................................................................................................ 12
Section 7 The o ry of Operati on ....................................................................................................... 14
Section 8 Maintenance and Troubleshooting ................................................................................ 14
8.1 Troubleshooting Power Problems ........................................................................................ 15
8.2 Troubleshooting Loop Fail Problems ................................................................................... 16
8.3 Troubleshooting Intermittent Loop Fail Problems ............................................................... 17
8.4 Troubleshooting Intermittent Detector Lock-Ups ................................................................ 17
8.5 Test Mod e O peration ........................................................................................................... 17
8.6 Things to Know About Loops .............................................................................................. 17
Section 1 General Description
This Operation Manual was written for people installing, operating, and troubleshooting Reno A & E Model T-110
inductive loop vehicle detectors. The Model T-110 inductive loop vehicle detector is a single channel, shelf-mount
type loop detector with delay and extension timing. The M odel T-110 is designed to meet or exceed the NEM A
Standards TS 1-1989.
The Model T-110 uses a microcontroller to monitor and process signals from the loop / lead-in circuit. The
operation of the detector is programmed with a front pane l mounted s ix-posit ion DIP switc h module to provide t he
following selections:
Seven S ensiti vity Levels (-ΔL/L%) and OFF.
Presence or Pulse Mode.
Four Fr equenc y Select ions.
Delay and extension timing settings are programmed w ith a twelve-position DIP sw itch module to provide de lay
timing intervals of 0 to 63 seconds and extension timing intervals of 0 to 15.75 seconds.
The Model T-110 constantly monito rs the loop circuit. During t his process, loop data is obtained and recorde d.
The data is compared to previous samples for the amount and rate of change. A slow rate of change, as is the case
with environmental drift, is continuously tracked. If a rapid change exceeds a threshold set by the sensitiv i t y le v e l,
the output is activated.
If the total inductance of the loop input network goes out of the range specified for the detector, or rapidly changes
by more than ±25%, the detector will ente r the Fail-Safe mode of operation. Fail-Safe operation, generates a
continuous CALL output state as long as a loop failure condition exists.
The detector has a single, dual color (green / red) Detect / Fail LED indicator. The LED provides an indication of
the detector’s output state, delay and/or extension timing settings, and loop failure conditions. Output state
conditions are indicated when the Detect / Fail LED is illuminated in a green state. Loop failure conditions are
indicated when the Detect / Fail LED is illumina te d in a red state.
The Detect / Fail LED will illuminate (red) to indicate that an Open Loop Failure or an inductance change
condition of greater th an +25% exists. The D ete c t / Fail LED will flas h (red) at a one Hz rate to indicate a Shorted
Loop Failure or an inductance change condition o f greater than -25% e xis ts . Eit he r i nd ica t io n w ill c o nt in ue fo r a s
long as the loop failure exists. If t he loop self-heals, the detector will resume operation in a normal manner, except
the Detect / Fail LED will flash (red) at a rate o f three 50 millisecond flashes per second, t hus providing an alert
that a loop fail condition has occurred. Any prior loop failure indication will continue until the detector is
manually reset or power is removed.
The Detect / Fail LED will illumina te (green) to indicate a vehicle presence in the loop area. If a prior Loop
Failure condition has occurred and detection occurs, the Detect / Fail LED will flash (red) at a rate of three 50
millisecond flashes per second followed by a single 750 millisecond flash (green). This prior Loop Failure
indication will continue until the detector is manually reset or power is removed.
In add ition, the Reno A & E Model T-110 has a Test Mode that uses the microco ntroller to verify the proper
operation of the detector’s controls and indicators (switches and LEDs). The detector’s loop oscillator circuit can
also be tested to verify the correct frequency range in each of the four frequency selections.
The Model T-110 Series is comprised of the following detectors:
Model T-110-R For NEMA TS-1 applications ca lling for a single channel, shelf
Model T-110-SS For NEMA TS-1 app lications calling for a single channel, shelf
mount detector with delay and extens ion timing and relay outputs.
mount detector with delay and e xtension timing and so lid state
outputs.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 1 of 20
Section 2 General Characteristics
2.1 LOOP FREQUENCY
There are four (4) selectable loop frequency settings (normally in the range of 20 to 100 kilohertz) for the detector.
The actual loop operating frequency is a function of the loop / lead-in network and the co mponents of the loop
oscillator circuit. Adjacent loops connected to different detectors may crosstalk and require changing of the
operating frequency of one of the loop circuits. If crosstalk is a problem, select another loop frequency for sta ble
operat ion. The fo ur f re q uency se le c t io ns are cont rolled w it h t w o D IP s w i tches (la beled 1 a nd 2) on the front pane l
mounted six-posi tion DIP switch module.
NOTE: The detector must be RESET after changing the frequency setting.
2.2 PRESENCE / PULSE MODE
Two modes of detector operation are available. Presence or Pulse Mode is selected by setting the state of a DIP
switch (labeled 3) on the front panel mounted six-position DIP switch module.
P
RESENCE MODE: Provides a Call hold time of at least four minutes (regardless of vehicle size) and typically
one to three hours for an automobile or truck. This is the factory default setting and the most common setting.
P
ULSE MODE: An ou tp ut p u lse of 1 25 ± 10 mi lli se co nd s d ura tio n is ge ne ra te d for e ac h ve h ic le e nte ri ng the loop
detection zone. Each detected vehicle is insta ntly tuned out if it remains in the loo p detection zone longer t han
two seconds. This enables detection of subsequent vehicles entering the loop detection zone. After each vehicle
leaves the loop detection zone, the detector resumes full sensitivity within one second.
NOTE: Changing the Presence / Pulse switch setting will RESET the detector.
2.3 SENSITIVITY
There are seven (7) selectable detector sensitivity levels plus OFF. The sensitivity levels are designed so that a one
level increase actually doubles the sensitivity and a one level decrease halves the sensitivity. The seven sensitivity
levels and OFF setting are selected via three DIP switches (labeled 4, 5, and 6) on the front panel mounted sixposition DIP switch module. (See Section 3.4 for actual detection levels and response times for each sensitivity
level.)
NOTE: Changing the sensitivity leve l s e tting will RESET the detector.
2.4 CALL EXTENSION
Call Extension can be ad justed from 0 to 15.75 in ¼-second s teps. C all Exte nsion set tings are co ntrolled w ith s ix
DIP switches (labeled 1 through 6) on the fro nt pane l mounted twelve-position DIP switch module . Call Extens ion
time starts counting down when the last ve hicle leaves the loop detect ion zo ne. I n the eve nt a ve hic le ent ers t he
loop detection zone before the extension time expires, the detector will return to the detect state (regardless of the
setting of the delay timer) and the extension timer will be reset. When the last vehicle leaves the loop detection
zone, full Extension time is reestablished and the detector begins counting down again. The detector will indicate
that the ext ens ion inte rva l is cur re ntly t imi ng b y fla sh ing t he D etec t / Fail LED a t 16 Hz ( gree n) w ith a 50% dut y
cycle. When operating in Pulse Mode, t he 125 millisecond pulse output w ill be extended by the amount o f time
programmed into the Extension timer.
2.5 CALL DELAY
Call Delay can be adjusted from 0 to 63 in one-second steps. Call Delay settings are controlled with six DI P
switches (labeled 7 through 12) o n the front panel mounted twelve-po sit io n DI P sw it ch mod ule. Ca ll D ela y t ime
starts counting down when a vehicle first enters the loop detection zone. If the Delay feature is activated, the
output will only be turned on after the selected delay time has passed with a vehicle continuously present in the
loop detection area. If a vehicle leaves the loop detection area during the delay interval, detection is aborted and
the next vehicle to enter the loop dete ction area will initiate a new full delay interval. Whenever the detector’s
Phase Green Input (call delay override) signal (pin J of the front panel mounted connector) is active (high state),
the Call Delay functio n for the detecto r is aborted and the Ca ll de lay time is forced to zero. The detector indicates
that a vehicle is being detected, but that the outputs are being delayed, by flashing the Detect / Fail LED at four Hz
(green) with a 50% duty cycle. When operat ing in Pulse Mode, the 125 millisecond pulse output will be delayed
by the amount o f time programme d into the Delay timer.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 2 of 20
2.6 AUDIBLE DETECT SIGNAL
The push butto n on the fr ont pa nel labe led BUZZER is used to enable an Audible Detect Signal. When this feature
is enab led ( on), a n aud ible s igna l wil l be activated whenever the detection zone is occupied. The audible signal
indicates actual occupancy of the loop detection zone.
2.7 TEST MODE
Test Mode uses the microcontroller to verify the proper operation of the detector’s controls and indicators
(switches and LEDs). The detector’s loop oscillator circuit is also tested to verify the correct frequency range in
each of the four frequency selections.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 3 of 20
Detect / Fail LED
Meaning
No Detect / No Loop Failure Condition
(No CALL Output)
Solid ON (Green)
Detect (CALL Output)
Solid ON (Orange)
Audible Detect Signal Activated, Detect ( CALL Output)
Vehicle detected, Delay Timing active,
No Detect (No CALL Output)
Audible Detect Signal Activated, Vehicle det ected,
Delay Timing active, No Detect (No CALL Output)
Detection zone vacant, Extension Timing active,
Detect (CALL Output)
Open Loop Failure
Inductance change condition of greater t han +25% exists
Shorted Loop Failure
Inductance change condition of greater t han -25% exists
Three 50 ms (Red) flashes per second
Loop Failure condition occurred but no longer exists
Section 3 Specifications
3.1 PHYSICAL
WEIGHT: 19.0 oz (538.7 gm).
S
IZE: 4.70 inches (11.94 cm) high x 2.25 inches (5.72 cm) wide x 5.30 inches (13.46 cm) deep excluding
connector. Connector adds .675 inches (1.71 cm) to depth measurement.
O
PERATING TEMPERATURE: -40°F to +180°F (-40°C to +82°C).
C
IRCUIT BOARD: Printed circuit boards are 0.062 inch thick FR4 material with 2 oz. copper on both sides and
plated through holes. Circuit board and components are conformal coated with polyur ethane.
C
ONNECTOR: MS 3102A-18-1P 10 pin male. See Section 3.6 for pin assignments.
3.2 ELECTRICAL
POWER: 89 to 135 VAC, 50/60 Hz, 6 Watts maximum.
L
OOP INDUCTANCE RANGE: 20 to 2000 micro henries w ith a Q factor of 5 or greater.
L
OOP INPUTS: Transformer isolated. The minimum capacitance added by the detector is 0.068 microfarad.
L
IGHTNING PROTECTION: Meets and/or exceeds all applicable NEMA TS 1 specifications for transient volta ge
protection.
R
ESET: Meets and/or exceeds NEMA TS 1 detector specifications. Each detector channel can be manually reset
by mome ntarily cha nging any sw itch positio n (except the frequency s witches). T he detector is also reset by
pressing the front panel mounted reset push button or by the return of power after a power loss.
R
ELAY RATING: The relay contacts are rated for 6 Amps maximum, 150 VDC maximum, and 180 Watts maximum
switched power.
S
OLID STATE OUTPUT RATING: Optically isolated. 30 VD C maximum collector (drain) to e mitter (source). 100
mA maximum saturation curre nt. 2 VDC maximum transistor sa turation voltage. The o utput is protected with a
33-volt Zener diode connected between the collector (drain) and emitter (source).
3.3 OPERATIONAL
DETECT / FAIL INDICATORS: The detector has a super bright, high inte nsity, two color (green / red) light e mitting
diode (LED) to indicate a CALL output and/or the status of any c urrent or prior loop failure conditions. A
continuous ON (green) state indicates a CALL output. A continuous ON (red) state indicates that a current open
loop failure condition or an inductance change condition of greater than +25% exists. This indication also
generates a CALL output. A one Hz (red) flash rate indicates that a current shorted loop failure condition or an
induct anc e c hange co nd itio n of gre ate r tha n -25 % exists. This indication also generates a CALL output. A flash
rate of three 50 millisecond (red) flashes indicates a prior loop failure condition. A flash rate of three 50
millisecond (red) flashes followed by a single 750 milliseco nd (green) flash ind icates a prior loop failure cond ition
and a current CALL output (detect state).
If the detector has the audible detect feature activated, the Detect / Fail LED will be illuminated in a n orange state
for any CALL output condition.
OFF
Four flashes per second (Green)
Four flashes per second (Orange)
16 flashes per second (Green)
Solid ON (Red)
One Hz flash rate (Red)
(50% D uty Cycle)
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 4 of 20
or
or
Detect / Fail LED
Meaning
Loop Failure condition occurred but no longer exists
Detect (CALL Output)
Loop Failure condition occurred but no longer exists,
Detect (CALL Output)
Loop Failure condition occurred but no longer exists
No Detect (No CALL Output)
Loop Failure condition occurred but no longer exists,
No Detect (No CALL Output)
Loop Failure condition occurred but no longer exists
Detect (CALL Output)
Three 50 ms (Red) flashes per second
followed by a single 750 ms (Green) flash
Three 50 ms (Red) flashes per second
followed by a single 750 ms (Orange) flash
Three 50 ms (Red) flashes per second
followed by four flashes per second (Green)
Three 50 ms (Red) flashes per second
followed by four flashes per second (Orange)
Three 50 ms (Red) flashes per second
followed by 16 flashes per second (Green)
and
Audible Detect Signal Activated,
and
and
Vehicle detected, Delay Timing active,
Audible Detect Signal Activated,
and
Vehicle detected, Delay Timing active,
and
Detection zone vacant, Extension Timing active,
RESPONSE TIME: Meets or exceeds NEMA TS 1 response time specifications. See Sensitivity, -∆L/L, & Typical
Response Times table for actual response times.
SELF-TUNING: The detector automatically tunes and is operational within two seconds after application of power
or after being reset. Full sensitivity and hold time require 30 seconds of operation.
E
NVIRONMENTAL & TRACKING: The detector is fully self-compensating for environmental changes a nd loop drift
over t he full te mperature range and the entire loop inductance r ange.
G
ROUNDED LOOP OPERATION: The lo op isolation transformer allows ope ration with poor quality loops (which may
include one short to ground at a single point).
L
OOP FEEDER LENGTH: Up to 5000 feet (1500 m) maximum with proper feeder cable and appropriate loops.
LOOP (FAIL) MONITOR: If the total inductance o f the detector’s loop input network goes out of the range specified
for the detector, or rapidly c hanges by mor e than ±25%, t he detector w ill immed iately enter the Fail-Safe mode of
operation. The Fail-Safe mode of operation generates a co ntinuous call d uring the lo op failure. The Detect / Fa il
LED will provide an indicatio n to identify the type of loop failure co ndition that exists. A continuo us ON (red)
state indicates that a current open loop failure condition or an inductance change condition of greater than +25%
exists. A one Hz (red) flash rate indicates that a curre nt shorted loop failure cond ition or an inductance cha nge
condition of greater than -25% exists. T his will co ntinue a s long a s the loop fault exists. However, if the detector
is reset, or power is momentarily lost, the detector will retune if the loop inductance is within the acceptable
range. If any type of loop fail ure occurs in one (or m ore) loop(s) in a gr oup of two or m ore loops wired i n
parallel, the detector will not respond with a Fail-Safe output following any type of reset. It is essential that
multiple loops wired to a common detector channel always be wired in series to ensure Fail-Safe operati on
under all circumstances. If the loop self-heals, the detector will resume operation in a normal manner except that
the Detect / Fail LED will begin to flash at a rate of three 50 millisecond (red) flashes per second, thus providing
an alert that the detector has experienced a prior loop failure condition. During this state, the Detect / Fail LED
will als o illuminate for 750 milliseconds (green) for a CALL output. The Detect / Fail LED will continue this
display pattern indicating the prior loop failure condition and/or detect state until the detector is manually reset or
power is removed.
FAIL-SAFE OUTPUTS: A detection output (CALL) is indicated by a closed relay contact (Relay output) or a
conducting state (Solid State o utput). The dete ctor output defau lts to a CALL state for an y loop failure cond ition
or upon loss of power.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 5 of 20
Sensitivity
Level
Industry
Reference
Switch 4 Switch 5 Switch
6
-∆L/L
Threshold
0 OFF
OFF
OFF
OFF
------
1 ON
OFF
OFF
0.64%
30 ±10 ms
2
Low
OFF
ON
OFF
0.32%
30 ±10 ms
3 ON
ON
OFF
0.16%
30 ±10 ms
4
Normal
OFF
OFF
ON
0.08%
30 ±10 ms
5 ON
OFF
ON
0.04%
30 ±10 ms
6
High
OFF
ON
ON
0.02%
30 ±10 ms
7 ON
ON
ON
0.01%
30 ±10 ms
DIP Switch
Function
Setting
Position
1
OFF
2
OFF
3
Presence / Pulse Mode
Presence
ON
4
OFF
5
ON
6
ON
Pin
Function (Relay Outputs)
Function (Solid State Outputs)
A
Power, Neutral, 120 VAC
Power, Neutral, 120 VAC
B
Output, Relay Common
Output, Emitter (Source)
C
Power, Line, 120 VAC
Power, Line, 120 VAC
D
Loop I nput
Loop I nput
E
Loop I nput
Loop I nput
F
Output, Relay Normally Open
Output, Collector (Drain)
G
Output, Relay Normally Closed
No Connection
I
No Connection
No Connection
J
Phase Green I nput
Phase Green Input
3.4 TABLE: SENSITIVITY, -∆L/L, AND TYPICAL RESPONSE TIME
Respons e Time
3.5 TABLE: DEFAULT SETTINGS (FRONT PANEL MOUNTED DIP SWITCH)
Frequency 0
Sensitivity 6
3.6 TABLE: PIN ASSIGNMENTS
H Chassis Ground Chassis Ground
NOTE: Relay contact states are shown with power applied, loop(s) connected, and no vehicle(s) present.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 6 of 20
T-110
VEHICLE DET ECT OR
SW O N
PRES PULS
SENSE
4
2
1
1
2
FREQ
LEVEL
32
16
8
4
2
1
D
E
L
A
Y
8
4
2
1
1/2
1/4
E
X
T
E
N
D
7 8
41 2
121110
9653
RESET
BUZZER
5
431
2 6
SENSITIVITY LEVEL
FREQUENCY
PRESENCE or PULSE
RESET PUSH BUTTON
DETECT / FAIL LED
EXTENSION TIMING
BUZZER PUSH BUTTON
Press to Activate / Deactivat e Audible
DELAY TIMING
Section 4 User Interface
• OFF = No CALL Output
• ON (Green) = CALL Output
• ON (Red) = Loop Failure
• ON (Orange) = CALL Output
(Audible Detect Feature
Activated)
• OFF = Pulse Mode
• ON = Presence Mode
• Switches 1 thru 6
• 0 to 15.75 Seconds
Detect Buzzer
NOTE: There are no internal switches or jumpers to set.
• 0 = OFF
• 7 = Highest
• 0 = HI
• 1 = MED HI
• 2 = MED LO
• 3 = LO
• Switches 7 thru 12
• 0 to 63 Seconds
Press to Reset Detector
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 7 of 20
Frequency
Switch 2
Switch 1
Switch Values
HI *
OFF *
OFF *
0 + 0 = 0 *
MED HI
ON
OFF
1 + 0 = 1
MED LO
OFF
ON
0 + 2 = 2
LO
ON
ON
1 + 2 = 3
* Factory default setting.
1 2 3 4
5
6
1 2 3 4 5 6
PRES/PULS
SENSE
4 2
1
FREQ LEVEL
2
1
1
2 3
4 5
6
1 2 3 4 5
6
PRES/PULS
SENSE
4 2
1
FREQ LEVEL
2 1
1 2 3 4 5 6
1 2 3
4 5
6
PRES/PULS
SENSE 4 2
1
FREQ LEVEL
2 1
Section 5 Installation an d Set-Up
The detector has a front panel mounted six-position DIP switch module to control the operation of the detector and
a front p anel mo unted twe lve-position DIP switch module to set Delay and/or Extension Timing. The various
switches can be set before or after the harness has been connected to the detector. The PRES / PULSE switch can
be pre-selected for the desired mode of operation. The SENSE LEVEL and FREQ switches may require
adjustment after the harness has been connected. When power is applied to the detector, the detector will
automatically tune to the loop circuit and begin operation within two seconds.
Connect the detector to an appropriately wired harness and apply power.
5.1 FRONT PANEL PROGRAMMING DIP SWITCHES
Frequency: Adjacent loops connected to different detectors may crosstalk and require
changing the operating frequency of one of the loop circ uits. If crosstalk is a problem,
select another loop frequency for stable op eration. The Mode l T-110 has four frequency
selections that allow altering the resonant frequency of the loop circuit. The four
frequency selections are controlled with two switches marked 1 and 2 on the DIP switch
module. The values (1 and 2) to the left of the DIP switch are assigned to the switch
when the switch is ON. If t he switch is OFF, t he switch has a value of zero (0 ). By
adding the swi tch ON and OFF values, the two switches can combine for values from 0
to 3 that indicate one of the four frequency selections. Use the following table as a
refere nce for t he s witc h se lec tio ns a nd fre q uenc y se tt ings. The fac tor y de fau lt se tti ng o f
these switches is switch 1 OFF and sw it ch 2 OFF ( H I).
NOTE: After changing the frequency s witch setting, it is nec essary to reset the detec tor
by momentarily changing one of the other s witch positions or by press ing the fr ont pa nel
mounted reset button..
Presence / Pulse Output Mode: One of two output modes can be selected for the
detector.
PRESENCE (PRES): When the switch is in the ON position, Presence Mode is selected.
Presence Mode provides a call hold time of at least four minutes (regardless of vehicle
size) and typically one to three hours for an automobile or truck.
PULSE (PULS): When the switch is in the OFF position, P ulse Mode is selected. Pulse
Mode will generate a single 125 millisecond pulse output for each vehicle entering the
loop detection zone. Any vehicle remaining in the loop detection zone longer than two
seconds will be tuned o ut providing full sensitivity for the vacant portion of the loop
detection zone. Full sensitivity for the entire loop detection zone is recovered within one
second following the departure of any vehicle that has occupied the loop detect ion zone
longer than two seconds.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 8 of 20
Sensitivity: The detector has seven sensitivity levels plus OFF that are selected with
three switches marked 4, 5, and 6 on the DIP switch module. The values (1, 2, and 4) to
the lef t of the DI P switch ar e assig ned to eac h switch w hen the sw itch is ON. If the
switch is OFF, the sw itch has a va lue o f zer o (0). By add ing t he sw itch ON and OFF
values , the t hree sw itches ca n comb ine for values f rom 0 to 7 indic ating w hich of the
seven sensitivity levels or OFF has been selected for the detector. Choose the lowest
sensitivity level that will co nsistently detect the s mallest vehicle that must b e detected.
Do not use a sensitivity level any higher than necessary. The following table shows the
actual sensitivity for eac h combinat ion of switch s ettings. T he factory default setting of
these switches is switch 4 OFF, switch 5 ON, and switch 6 ON (sensit i vity level 6, -ΔL/L
= 0.02%).
Sensitivity
Level
Industry
Reference
-∆L/L
Threshold
0
OFF
OFF
OFF
OFF
N/A
1 ON
OFF
OFF
0.64%
2
Low
OFF
ON
OFF
0.32%
3 ON
ON
OFF
0.16%
4
Normal
OFF
OFF
ON
0.08% 5
ON
OFF
ON
0.04%
6 *
Hig h *
OFF *
ON *
ON *
0.02% * 7
ON
ON
ON
0.01%
* Factory default setting.
Extension
(Seconds)
0
OFF
OFF
OFF
OFF
OFF
OFF
0 + 0 + 0 + 0 + 0 + 0 = 0
0.25
ON
OFF
OFF
OFF
OFF
OFF
¼ + 0 + 0 + 0 + 0 + 0 = 0.25
0.50
OFF
ON
OFF
OFF
OFF
OFF
0 + ½ + 0 + 0 + 0 + 0 = 0.50
0.75
ON
ON
OFF
OFF
OFF
OFF
¼ + ½ + 0 + 0 + 0 + 0 = 0.75
1.00
OFF
OFF
ON
OFF
OFF
OFF
0 + 0 + 1 + 0 + 0 + 0 = 1.00
1.25
ON
OFF
ON
OFF
OFF
OFF
¼ + 0 + 1 + 0 + 0 + 0 = 1.25
1.50
OFF
ON
ON
OFF
OFF
OFF
0 + ½ + 1 + 0 + 0 + 0 = 1.50
1.75
ON
ON
ON
OFF
OFF
OFF
¼ + ½ + 1 + 0 + 0 + 0 = 1.75
2.00
OFF
OFF
OFF
ON
OFF
OFF
0 + 0 + 0 + 2 + 0 + 0 = 2.00
2.25
ON
OFF
OFF
ON
OFF
OFF
¼ + 0 + 1 + 0 + 0 + 0 = 2.25
2.50
OFF
ON
OFF
ON
OFF
OFF
0 + ½ + 0 + 2 + 0 + 0 = 2.50
2.75
ON
ON
OFF
ON
OFF
OFF
¼ + ½ + 0 + 2 + 0 + 0 = 2.75
3.00
OFF
OFF
ON
ON
OFF
OFF
0 + 0 + 1 + 2 + 0 + 0 = 3.00
3.25
ON
OFF
ON
ON
OFF
OFF
¼ + 0 + 1 + 2 + 0 + 0 = 3.25
3.50
OFF
ON
ON
ON
OFF
OFF
0 + ½ + 1 + 2 + 0 + 0 = 3.50
3.75
ON
ON
ON
ON
OFF
OFF
¼ + ½ + 1 + 2 + 0 + 0 = 3.75
4.00
OFF
OFF
OFF
OFF
ON
OFF
0 + 0 + 0 + 0 + 4 + 0 = 4.00
4.25
ON
OFF
OFF
OFF
ON
OFF
¼ + 0 + 0 + 0 + 4 + 0 = 4.25
4.50
OFF
ON
OFF
OFF
ON
OFF
0 + ½ + 0 + 0 + 4 + 0 = 4.50
4.75
ON
ON
OFF
OFF
ON
OFF
¼ + ½ + 0 + 0 + 4 + 0 = 4.75
5.00
OFF
OFF
ON
OFF
ON
OFF
0 + 0 + 1 + 0 + 4 + 0 = 5.00
5.25
ON
OFF
ON
OFF
ON
OFF
¼ + 0 + 1 + 0 + 4 + 0 = 5.25
5.50
OFF
ON
ON
OFF
ON
OFF
0+ ½ + 1 + 0+ 4 + 0 = 5.50
5.75
ON
ON
ON
OFF
ON
OFF
¼ + ½ + 1 + 0+ 4 + 0= 5.75
6.00
OFF
OFF
OFF
ON
ON
OFF
0 + 0 + 0 + 2 + 4 + 0 = 6.00
6.25
ON
OFF
OFF
ON
ON
OFF
¼ + 0 + 0 + 2 + 4 + 0 = 6.25
6.50
OFF
ON
OFF
ON
ON
OFF
0 + ½ + 0 + 2 + 4 + 0 = 6.50
6.75
ON
ON
OFF
ON
ON
OFF
¼ + ½ + 0 + 2 + 4 + 0 = 6.75
7.00
OFF
OFF
ON
ON
ON
OFF
0 + 0 + 1 + 2 + 4 + 0 = 7.00
7.25
ON
OFF
ON
ON
ON
OFF
¼ + 0 + 1 + 2 + 4 + 0 = 7.25
7.50
OFF
ON
ON
ON
ON
OFF
0 + ½ + 1 + 2 + 4 + 0 = 7.50
7.75
ON
ON
ON
ON
ON
OFF
¼ + ½ + 1 + 2 + 4 + 0 = 7.75
8.00
OFF
OFF
OFF
OFF
OFF
ON
0 + 0 + 0 + 0 + 0 + 8 = 8.00
8.25
ON
OFF
OFF
OFF
OFF
ON
¼ + 0 + 0 + 0 + 0 + 8 = 8.25
8.50
OFF
ON
OFF
OFF
OFF
ON
0 + ½ + 0 + 0 + 0 + 8 = 8.50
8.75
ON
ON
OFF
OFF
OFF
ON
¼ + ½ + 0 + 0 + 0 + 8 = 8.75
Switch 4 Switch 5 Switch 6
5.2 FRONT PANEL DELAY AND EXTENSION TIMING DIP SWITCHES
The Model T-110 incorporates a front panel mounted, twe lve-position DIP switch module that is used to set Call
Delay and Call Extensi on times .
Extension Timi ng: The detecto r can be set to pro vide an Extension Timing interval of 0 to 15.75 seco nds in ¼second increments. Ca ll Extension sett ings are controlled via six DIP switches marked 1, 2, 3, 4, 5, and 6 on t he
DIP switch module. The values ( ¼, ½, 1, 2, 4, and 8) to t he left of the DIP switch are assigned to each switch
when t he sw itc h is O N. I f the switc h is OF F, the swit ch h as a value of z ero ( 0). By a ddin g the s wit ch ON and
OFF values, the s i x switc hes can combine for values from 0 to 15.7 5 indica ting the length of the E xtensio n Timing
interval that has been selected. The following table shows the actual Extension Time setting for each combination
of switch settings. The factory defa ult setting of all of these switches is OFF (no Extension T ime pro grammed).
Time
Setting
Switch 1
(1/4)
Switch 2
(1/2)
Switch 3
(1)
Switch 4
(2)
Switch 5
(4)
Switch 6
(8)
Switc h Values
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 9 of 20
Extension
(Seconds)
9.00
OFF
OFF
ON
OFF
OFF
ON
0 + 0 + 1 + 0 + 0 + 8 = 9.00
9.25
ON
OFF
ON
OFF
OFF
ON
¼ + 0 + 1 + 0 + 0 + 8 = 9.25
9.50
OFF
ON
ON
OFF
OFF
ON
0 + ½ + 1 + 0 + 0 + 8 = 9.50
9.75
ON
ON
ON
OFF
OFF
ON
¼ + ½ + 1 + 0 + 0 + 8 = 9.75
10.00
OFF
OFF
OFF
ON
OFF
ON
0 + 0 + 0 + 2 + 0 + 8 = 10.00
10.25
ON
OFF
OFF
ON
OFF
ON
¼ + 0 + 0 + 2 + 0 + 8 = 10.25
10.50
OFF
ON
OFF
ON
OFF
ON
0 + ½ + 0 + 2 + 0 + 8 = 10.50
10.75
ON
ON
OFF
ON
OFF
ON
¼ + ½ + 0 + 2 + 0 + 8 = 10.75
11.00
OFF
OFF
ON
ON
OFF
ON
0 + 0 + 1 + 2 + 0 + 8 = 11.00
11.25
ON
OFF
ON
ON
OFF
ON
¼ + 0 + 1 + 2 + 0 + 8 = 11.25
11.50
OFF
ON
ON
ON
OFF
ON
0 + ½ + 1 + 2 + 0 + 8 = 11.50
11.75
ON
ON
ON
ON
OFF
ON
¼ + ½ + 1 + 2 + 0 + 8 = 11.75
12.00
OFF
OFF
OFF
OFF
ON
ON
0 + 0 + 0 + 0 + 4 + 8 = 12.00
12.25
ON
OFF
OFF
OFF
ON
ON
¼ + 0 + 0 + 0 + 4 + 8 = 12.25
12.50
OFF
ON
OFF
OFF
ON
ON
0 + ½ + 0 + 0 + 4 + 8 = 12.50
12.75
ON
ON
OFF
OFF
ON
ON
¼ + 0 + 1 + 0 + 4 + 8 = 12.75
13.00
OFF
OFF
ON
OFF
ON
ON
0 + 0 + 1 + 0 + 4 + 8 = 13.00
13.25
ON
OFF
ON
OFF
ON
ON
¼ + 0 + 1 + 0 + 4 + 8 = 13.25
13.50
OFF
ON
ON
OFF
ON
ON
0 + ½ + 1 + 0 + 4 + 8 = 13.50
13.75
ON
ON
ON
OFF
ON
ON
¼ + ½ + 1 + 0 + 4 + 8 = 13.75
14.00
OFF
OFF
OFF
ON
ON
ON
0 + 0 + 0 + 2 + 4 + 8 = 14.00
14.25
ON
OFF
OFF
ON
ON
ON
¼ + 0 + 0 + 2 + 4 + 8 = 14.25
14.50
OFF
ON
OFF
ON
ON
ON
0 + ½ + 0 + 2 + 4 + 8 = 14.50
14.75
ON
ON
OFF
ON
ON
ON
¼ + ½ + 0 + 2 + 4 + 8 = 14.75
15.00
OFF
OFF
ON
ON
ON
ON
0 + 0 + 1 + 2 + 4 + 8 = 15.00
15.25
ON
OFF
ON
ON
ON
ON
¼ + 0 + 1 + 2 + 4 + 8 = 15.25
15.50
OFF
ON
ON
ON
ON
ON
0 + ½ + 1 + 2 + 4 + 8 = 15.50
15.75
ON
ON
ON
ON
ON
ON
¼ + ½ + 1 + 2 + 4 + 8 = 15.75
Delay
(Seconds)
0
OFF
OFF
OFF
OFF
OFF
OFF
0 + 0 +0 + 0 + 0 + 0 = 0
1
ON
OFF
OFF
OFF
OFF
OFF
1 + 0 + 0 + 0 + 0 + 0 = 1
2
OFF
ON
OFF
OFF
OFF
OFF
0 + 2 + 0 + 0 + 0 + 0 = 2
3
ON
ON
OFF
OFF
OFF
OFF
1 + 2 + 0 + 0 + 0 + 0 = 3
4
OFF
OFF
ON
OFF
OFF
OFF
0 + 0 + 4 + 0 + 0 + 0 = 4
5
ON
OFF
ON
OFF
OFF
OFF
1 + 0 + 4 + 0 + 0 + 0 = 5
6
OFF
ON
ON
OFF
OFF
OFF
0 + 2 + 4 + 0 + 0 + 0 = 6
7
ON
ON
ON
OFF
OFF
OFF
1 + 2 + 4 + 0 + 0 + 0 = 7
8
OFF
OFF
OFF
ON
OFF
OFF
0 + 0 + 0 + 8 + 0 + 0 = 8
9
ON
OFF
OFF
ON
OFF
OFF
1 + 0 + 0 + 8 + 0 + 0 = 9
10
OFF
ON
OFF
ON
OFF
OFF
0 + 2 + 0 + 8 + 0 + 0 = 10
11
ON
ON
OFF
ON
OFF
OFF
1 + 2 + 0 + 8 + 0 + 0 = 11
12
OFF
OFF
ON
ON
OFF
OFF
0 + 0 + 4 + 8 + 0 + 0 = 12
13
ON
OFF
ON
ON
OFF
OFF
1 + 0 + 4 + 8 + 0 + 0 = 13
14
OFF
ON
ON
ON
OFF
OFF
0 + 2 + 4 + 8 + 0 + 0 = 14
15
ON
ON
ON
ON
OFF
OFF
1 + 2 + 4 + 8 + 0 + 0 = 15
16
OFF
OFF
OFF
OFF
ON
OFF
0 + 0 + 0 + 0 + 16 + 0 = 16
17
ON
OFF
OFF
OFF
ON
OFF
1 + 0 + 0 + 0 + 16 + 0 = 17
18
OFF
ON
OFF
OFF
ON
OFF
0 + 2 + 0 + 0 + 16 + 0 = 18
19
ON
ON
OFF
OFF
ON
OFF
1 + 2 + 0 + 0 + 16 + 0 = 19
Time
Setting
Delay Timing: The detector can be set to provide a Delay Timing interval of 0 to 63 seconds in 1-second
increments. Call Delay settings are controlled via six DIP switches marked 7, 8, 9, 10, 11, and 12 on the DIP
switch module. The values (1, 2, 4, 8, 16 and 32) to the left of the DIP switch are a ssigned to each switch when the
switch is O N. If the switch is O F F, t he s w it c h h a s a value o f ze ro (0 ). B y a dding the s wit c h ON and OFF values,
the six switches can comb ine for values fro m 0 to 63 i ndicat ing the lengt h of the Delay T imin g inter val tha t has
been selected. The following table shows the actual Delay Time setting for each combination of switch settings.
The factory default setting of all of these s witches is OFF (no Delay Time pro gr ammed).
Switch 1
(1/4)
Switch 2
(1/2)
Switch 3
(1)
Switch 4
(2)
Switch 5
(4)
Switch 6
(8)
Switc h Values
Time
Setting
Switch 7
(1)
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 10 of 20
Switch 8
(2)
Switch 9
(4)
Switch
10 (8)
Switch
11 (16)
Switch
12 (32)
Switc h Values
Delay
(Seconds)
20
OFF
OFF
ON
OFF
ON
OFF
0 + 0 + 4 + 0 + 16 + 0 = 20
21
ON
OFF
ON
OFF
ON
OFF
1 + 0 + 4 + 0 + 16 + 0 = 21
22
OFF
ON
ON
OFF
ON
OFF
0 + 2 + 4 + 0 + 16 + 0 = 22
23
ON
ON
ON
OFF
ON
OFF
1 + 2 + 4 + 0 + 16 + 0 = 23
24
OFF
OFF
OFF
ON
ON
OFF
0 + 0 + 0 + 8 + 16 + 0 = 24
25
ON
OFF
OFF
ON
ON
OFF
1 + 0 + 0 + 8 + 16 + 0 = 25
26
OFF
ON
OFF
ON
ON
OFF
0 + 2 + 0 + 8 + 16 + 0 = 26
27
ON
ON
OFF
ON
ON
OFF
1 + 2 + 0 + 8 + 16 + 0 = 27
28
OFF
OFF
ON
ON
ON
OFF
0 + 0 + 4 + 8 + 16 + 0 = 28
29
ON
OFF
ON
ON
ON
OFF
1 + 0 + 4 + 8 + 16 + 0 = 29
30
OFF
ON
ON
ON
ON
OFF
0 + 2 + 4 + 8 + 16 + 0 = 30
31
ON
ON
ON
ON
ON
OFF
1 + 2 + 4 + 8 + 16 + 0 = 31
32
OFF
OFF
OFF
OFF
OFF
ON
0 + 0 + 0 + 0 + 0 + 32 = 32
33
ON
OFF
OFF
OFF
OFF
ON
1 + 0 + 0 + 0 + 0 + 32 = 33
34
OFF
ON
OFF
OFF
OFF
ON
0 + 2 + 0 + 0 + 0 + 32 = 34
35
ON
ON
OFF
OFF
OFF
ON
1 + 2 + 0 + 0 + 0 + 32 = 35
36
OFF
OFF
ON
OFF
OFF
ON
0 + 0 + 4 + 0 + 0 + 32 = 36
37
ON
OFF
ON
OFF
OFF
ON
1 + 0 + 4 + 0 + 0 + 32 = 37
38
OFF
ON
ON
OFF
OFF
ON
0 + 2 + 4 + 0 + 0 + 32 = 38
39
ON
ON
ON
OFF
OFF
ON
1 + 2 + 4 + 0 + 0 + 32 = 39
40
OFF
OFF
OFF
ON
OFF
ON
0 + 0 + 0 + 8 + 0 + 32 = 40
41
ON
OFF
OFF
ON
OFF
ON
1 + 0 + 0 + 8 + 0 + 32 = 41
42
OFF
ON
OFF
ON
OFF
ON
0 + 2 + 0 + 8 + 0 + 32 = 42
43
ON
ON
OFF
ON
OFF
ON
1 + 2 + 0 + 8 + 0 + 32 = 43
44
OFF
OFF
ON
ON
OFF
ON
0 + 0 + 4 + 8 + 0 + 32 = 44
45
ON
OFF
ON
ON
OFF
ON
1 + 0 + 4 + 8 + 0 + 32 = 45
46
OFF
ON
ON
ON
OFF
ON
0 + 2 + 4 + 8 + 0 + 32 = 46
47
ON
ON
ON
ON
OFF
ON
1 + 2 + 4 + 8 + 0 + 32 = 47
48
OFF
OFF
OFF
OFF
ON
ON
0 + 0 + 0 + 0 + 16 + 32 = 48
49
ON
OFF
OFF
OFF
ON
ON
1 + 0 + 0 + 0 + 16 + 32 = 49
50
OFF
ON
OFF
OFF
ON
ON
0 + 2 + 0 + 0 + 16 + 32 = 50
51
ON
ON
OFF
OFF
ON
ON
1 + 2 + 0 + 0 + 16 + 32 = 51
52
OFF
OFF
ON
OFF
ON
ON
0 + 0 + 4 + 0 + 16 + 32 = 52
53
ON
OFF
ON
OFF
ON
ON
1 + 0 + 4 + 0 + 16 + 32 = 53
54
OFF
ON
ON
OFF
ON
ON
0 + 2 + 4 + 0 + 16 + 32 = 54
55
ON
ON
ON
OFF
ON
ON
1 + 2 + 4 + 0 + 16 + 32 = 55
56
OFF
OFF
OFF
ON
ON
ON
0 + 0 + 0 + 8 + 16 + 32 = 56
57
ON
OFF
OFF
ON
ON
ON
1 + 0 + 0 + 8 + 16 + 32 = 57
58
OFF
ON
OFF
ON
ON
ON
0 + 2 + 0 + 8 + 16 + 32 = 58
59
ON
ON
OFF
ON
ON
ON
1 + 2 + 0 + 8 + 16 + 32 = 59
60
OFF
OFF
ON
ON
ON
ON
0 + 0 + 4 + 8 + 16 + 32 = 60
61
ON
OFF
ON
ON
ON
ON
1 + 0 + 4 + 8 + 16 + 32 = 61
62
OFF
ON
ON
ON
ON
ON
0 + 2 + 4 + 8 + 16 + 32 = 62
63
ON
ON
ON
ON
ON
ON
1 + 2 + 4 + 8 + 16 + 32 = 63
Time
Setting
Switch 7
(1)
Switch 8
(2)
Switch 9
(4)
Switch
10 (8)
Switch
11 (16)
Switch
12 (32)
Switc h Values
5.3 FRONT PANEL MOUNTED PUSHBUTTON – AUDIBLE DETECT SIGNAL (BUZZER)
The push butto n on the fr ont pa nel labe led BUZZER is used to enable an Audible Detect Signal. When this feature
is enabled (on), an audible signal will be activated whenever the detection zone is occupied. The audible signal
indicates actual occupancy of the loop detection zone. To activate this feature, press the push button. A short (50
millisecond) audible signal confirms the activation of the feature. To deactivate this feature, press and hold the
push button f or one s econd. A long (250 millisecond) audib le signal confir ms the deactivat ion o f the feature. This
feature is automatically disabled 15 minutes after activation or on loss of power.
NOTE: When operating in Pulse Mode, the audible detect signal will cease once a vehicle has occupied the
detection zone for more than two seconds.
5.4 PC BOARD MOUNTED JUMPER – TEST MODE
Test Mode uses the microcontroller to verify the proper operation of the detector’s controls and indicators
(switches and LEDs). When connected to loops of the appropriate inductance (100 microhenries), the detector’s
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 11 of 20
Detect / Fail LED
Meaning
OFF
No Loop Failure
Solid ON (Red)
Open Loop Failure Or Inductance change condition of greater than +25% exists
One Hz flash rate (Red) (50% Duty Cycle )
Short e d Loop Failure Or Inductance change condition o f great er than -25% exists
Three 50 ms (Red) flashes per second
Loop Failure condition occurred but no longer exists
loop oscillator circuit can also be tested to verify the correct frequency range in each of the four frequency
selections. Test Mode is selected by placing a shorting jumper (shunt) across the PC Board mounted two-pin
header labeled TEST. Refer to Section 8.5 for a complete explanation of Test Mode operation.
5.5 FONT PANEL MOUNTED PUSHBUTTON – DETECTOR RESET
The push butto n on the fr ont panel labeled RESET is used to reset the detector.
5.6 LOOP FAIL INDICATIONS
The Detect / Fail LED indicates loop failure problems according to the following table. The Detect / Fail LED is
illuminated in a red state to provide an indication of either a current or prior out of tolerance (loop failure)
condition. A continuous ON (red) state indicates that a current open loop failure condition or an inductance change
condition of greater than +25% exists. A one Hz (red) flash rate indicates that a current shorted loop fa ilure
condit ion or a n induc tance cha nge cond itio n of gre ater t han -25% exists. If the loop self-heals, the detector will
resume operation in a normal manner except that the Detect / Fail LED will begin to flash at a rate of three 50
millisecond (red) flashes per second, thus providing an alert that the detector has experienced a prior loop failure
condition.
5.7 RESETTING THE DETEC TOR
Changing the position of any fro nt panel mounted programming DIP sw itc h (e xcept the Frequency switches) resets
the detector. Changes made to any of the Delay and/or Extension Timing DIP switches do not reset the detector.
The detector is also reset by pressing the front panel mounted reset push button or by the return of power after a
power loss.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 12 of 20
Switch
Squaring
Loop
Loop
Loop
FREQ
120 VAC
Neutral
VS
+5 VDC
GND
Switch
Section 6 Block Diagram
Circuit
Switches
Input
Isolation
Line
Power
Supply
Oscillator
Clock
20 MHz
Reset
Buzzer
Detect
Output
Micro
Controller
Front Panel
Programming
DIP Switches
Front Panel
Timing
DIP Switches
Detect / Fail
LED
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 13 of 20
Section 7 Theory of Operation
The Reno A & E Model T-110 Detector digitally measures changes in the resonant frequency of a parallel tuned
resonant circuit (loop / lead-in) to determine if a vehicle has entered the detection zone. The detector applies an
excitat i on v o lta ge t o the loop circuit resulting in the loop oscillating at its resonant frequency. The current flow in
the loop wire creates magnetic fields around the loop wire. When a vehicle passes over the loop area, the
conductive metal of the vehicle causes a loading of the loop’s magnetic fields. The loading decreases the loop
inductance, which causes the resonant frequency to increase. By continuously sampling the loop’s resonant
freque ncy, the magnitude and rate o f change c an be dete rmined. If the freq uency cha nge exceeds a selectable
threshold (set by the sensitivity sett ings), the detecto r will activate an outp ut signal. If the rate of cha nge is slow,
typical of environmental drift, the detector will continuously track a nd compensate for the change. The detector
also monitors the loop frequency for out of range conditions such as an opened or shorted loop circuit.
The detector’s oscillator circ uit supplies the exc itation volta ge that is coupled to the loop circ uit by a loop isola tion
trans former. T he trans former provides high common mode isolation between the loop and detector electronics,
which allows the detector to operate on poor quality loops including a s ingle s hort to ground. The transformer also
limits the amount of static energy (light ning) that can transfer to the detector electronics. A spark gap transient
suppression device is connected across the loop inputs to the isolation transformer. This device will dissipate static
charges prior to the transformer. The loop input is also filtered for 60-cycle noise. A network of three capacitors is
connected to the detector side of the isolation transformer. The capacitors can be switched in or out of the
oscillator circuit to shift the frequency of the loop circuit t hus providing frequency separation betwee n adjacent
loops.
The sine wave from the loop circuit is square d for the microcontro ller to digitally meas ure the period of severa l
cycles. A high-speed clock sets a reference count for the period in a counter. If the frequency increases, the period
is shorter and the period count decreases. By comparing the new count with the reference count, a percentage of
change can be calculated that indirectly relates to the inductance change. If the magnitude of the change exceeds a
selectable threshold (sensitivity setting), the detector activates the output device.
The rate of change is also monitored. Slow rates of change typical of environmental drift are tracked and
automatically compensated for. If the total inducta nce o f the loop input network goes out of the range specified for
the detector, or rapidly chan ges by more than ±25%, the detector will immediately enter the Fail-Safe mode of
operation. Fail-Safe operation generates a continuous call output in Presence Mode or Pulse Mode. The Detect /
Fail LED will turn ON (red) or flash (red) at a one Hz rate and remain on or continue flashing for as long as the
loop failure exists. If the loop self-heals, the detector will resume operation in a normal manner; except the Detect
/ Fail LED will begin to flash at a rate of three red flashes per second, thus providing an alert of a prior Loop Fail
condition. The Detect / Fail LED will con tinue indicating the last loop failure condition until the detector is
manually reset or power is removed.
The detector is des igned to operate from A.C. power sources providing 120 VAC. On board regulators provide
regulated voltages so that the detector can safely operate over the full input voltage range of 89 VAC to 135 VAC.
The unit is also provided with an external reset capability. When the front panel mounted reset butto n is pressed,
the dete cto r is i mmed iate ly res et. C hang ing a ny fro nt pa nel p rogr ammi ng DI P sw itch (e xcep t t he freq uenc y DIP
switches) resets the detector.
Operating parameters that can be selected by means of t he f ro nt p anel DIP s w i tches are Loo p Fr equency, P r es e nc e
/ Pulse Mo de, Sens itivit y, Delay T iming, and Exte nsion Ti ming. A fron t panel mo unted p ush butto n is used fo r
activation of an audible detect signal. The loop frequency switches are directly connected to the tuning capacitors
in the loop oscillator c ircuit. The settings o f the remaining switches are s trobed into the microprocess or. The
microprocessor provides a n output signa l; an output line for the detec tor. The o utp ut li ne dr ive s e ithe r a fai l-safe
optica l ly iso la te d t ra ns is to r or a mec ha n ica l re la y. Solid state outp ut devices provide faster turn ON and tur n OFF
times thus giving more accurate infor mation when the detector is used in speed and/or occ upancy applications.
The output signal is connected to a dual color (green / red), front panel mounted Detect / Fail LED. The Detect /
Fail LED is no rma lly ex ti nguis hed whe n ther e is no det ect outp ut, the loo p is i n tole ra nce, and t here have bee n no
previous failure conditio ns. The Detect / Fail LED will be s teady ON (gree n) when a current de tect output state
exists. The Detect / Fail LED will be steady ON (red) when a current open loop failure or an inductance change
condition of more tha n 25% e xists. The D etec t / Fa il LED w ill flas h at a o ne Hz ra te (red ) w he n a c urre nt s horte d
loop failure or an inductance change condition of less than 25% exists. When the Detect / Fail LED flashes at a
rate of three 50 millisecond flashes per second (red), it is an indication that the loop is currently in toleranc e, but
the detector has previously experienced an out of tolerance condition. If a current detect output state exists and the
detector has previously experienced an out of tolerance condition, the Detect / Fail LED will flash at a rate of three
50 millisecond flashes per second (red) followed by a single 750 millisecond flash (green). Either of these prior
failure Detect / Fail LED flashing conditions will be reset whenever the detector is reset or power is interrupted.
The Reno A & E Model T-110 detector is designed and manufactured using the latest available technology in
electronic design and manufacturing; thus providing the highest possible performance and reliability. Once
properly installed a Reno A & E loop detector will provide years of trouble free operation.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 14 of 20
Symptom
Where To Start
See Troubleshooting Power Problems.
Check for sensitivity set extremely low (0 to 2).
LOOP FAIL indication
(LED ON Red or flashing Red at a one Hz rate).
Previous LOOP FAIL indication
and detector appears to be working correctly.
Detector intermittently stays in the Call state
(LED ON Green).
Section 8 Maintenance and Troubleshooting
The Reno A & E Model T-110 Detector requires no mainte nance. If yo u are having problems wit h your Mode l T110 detector, use the troubleshooting chart below to help determine the cause of the problem.
LED is n o t lit and detector does not respond to traffic.
See Troubleshooting Loop Fail Problems.
(LED flashing three times per second Red)
See Troubleshooting Intermittent Loop Fail Problems.
See Troubleshooting Intermittent Det ect or Loc k Ups.
8.1 TROUBLESHOOTING POWER PROBLEMS
Does the LED turn ON (Green) w hen the detector is powered up and a vehicle is over the loop connected to the
detector?
NO, Do any of the detectors in the cabinet do anything when powered up and a vehicle is over one of the
loops connected to any of the detectors?
NO, Check Power Supply voltage. Is it greater than 89 VAC and less than 135 VAC?
NO, Disconnect all devices that are connected to the Pow er Supply. C heck the
Power Supply voltage again. Is it great er than 89 VAC and less than 135 VAC?
NO, Replace the Power Supply.
YES, Reconnect the disconnected devices, one at a time, until the voltage
is no longer valid. Replace the device that, when reconnected, causes the
Power Supply voltage to be invalid. Can all devices be connected at the
same time and work correctly?
NO, Power Supply is defective or under rated for the number of
units connected to the power supply. Replace with an
appropiate unit.
YES, Replaced device was defective.
YES, Wiring from Power Supply to cabinet is incorrect or defective.
YES, Swap the detector with a working detector elsewhere in the cabinet. Did the problem
follow the detector?
NO, The harness is defective. Confirm correct wiring of the harness and that the
harness connector is not defective or damaged.
YES, The swapped unit is defective. Replace the unit.
YES, Probably not a power related problem.
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8.2 TROUBLESHOOTING LOOP FAIL PROBLEMS
Is the front pa nel LED show ing a Loop Failure indication (ON Red or one Hz flash rate Red)?
NO, The detector has tuned up to the existing loop / lead-in circuit and is within accep ta ble limits.
YES, Is there a loop connected to this detector?
NO, Disable the detector b y setting the sensitivity level to 0 (se t D I P s witches 4,5, and 6 to the
OFF position) and the Loop Failure indication will cease.
YES, There is an open, a high resistance, or a s hort in the loop / lead-in c ircuit. Disconnect
the existing loop at the field terminals in the cabinet and connect a test loop to t he field
terminals. Reset the detector. Did the Loop Failure indication cease?
NO, The problem is in the cabinet. Replace the detector with a known good unit.
Did the Loop Failure indication cease?
NO, The detector is not the problem. Measure the resistance from each
loop terminal to the harness connector in the cabinet. It should read less
than 0.5 Ohms for both leads. Check all wiring from terminal block to t he
harness connector in the cabinet. Also check that the harness connector
itself is not defective.
YES, The replaced unit was defective.
YES, The problem is in the field. The next step is to determine if the loop / lead-in
circuit is shorted. Do this by c onnecting the loop in pa rallel with t he test loop that
you have installed. Reset the detector. Did the Loop Failure indication cease?
NO, There is either a short in the loop / lead-in circuit or insufficient
inductance in the loop / lead-in circuit. Disconnect the loop in the
cabinet. Connect a MegOhm meter to one of the lead-in wires and earth
ground. Is the resistance greater than 50 megohms?
NO, There is leakage to earth ground in the loop / lead-in
circuit. Disconnect the loop from the lead-in cable. Measure
the resistance between one of the loop wires and earth ground.
Is the resistance greater than 50 megohms?
NO, The loop is damaged. R eplace t he loop.
YES, The lead-in cable is defective. Check all
splices. Replace the lead-in cable if necessary.
YES, The problem is insufficient inductance in the loop / leadin circuit or a short in the lead-in cable. Leave the loop
disconnected in the cabinet. Disconnect the loop from the leadin cable. Using a MegOhm meter, measure the resistance
between the two lead-in wires. Is the resistance greater than 50
megohms?
NO, The lead-in cable is defective. Check all splices.
Replace the lead-in cable if necessary.
YES, This indicates too few turns in the lo op itself or
some of the turns are shorted to each other. In either
case the loop must be replaced to correct the
problem.
YES, There is an open or high resistance in the field. Disconnect the loop
in the cabinet. Measure the resistance of the loop / lead-in circuit (from
one lead of the loop to the other). Is the resistance below five Ohms?
NO, Measure the resistance as close as possible to where the
loop enters the pavement. Is the resistance below two Ohms?
NO, The loop is probably damaged. Replace the
loop.
YES, The lead-in cable is defective. Check all
splices. Replace the lead-in cable if necessary.
YES, The p ro b lem is p ro ba b l y e xc e s sive ind uc t a nc e . Are t he re
several loops connected in series for the loop / lead-in circuit?
NO, This is typically caused by having too many
turns in a large loop. Replace the loop with one that
has an inductance of less than 2000 microhenries
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 16 of 20
Switch Label
Switch #
LED Indications and Outputs
SENSE LEVEL 4
6
DETECT / FAIL LED ILLUMINATED - GREEN
SENSE LEVEL 2
5
DETECT / FAIL LED ILLUMINATED - RED
SENSE LEVEL 1
4
DETECT / FAIL LED ILLUMINATED - GREEN
PRES PULS
3
DETECT / FAIL LED ILLUMINATED - RED
.
YES, If possible, connecting each loop to its own
detector is preferred. Or try a parallel wiring
arrangement for the loops if separate detection
channels are not possible.
8.3 TROUBLESHOOTING INTERMITTENT LOOP FAIL PROBLEMS
Intermittent Loop Fa il problems tend to b e associated with bad splices in the loop / lead-in circu it, shorts in the
loop / lead-in circ uit, shorts to earth ground in the loop / lead-in circuit, or loose connections or bad solder jo ints in
the signal cabinet. If you have any splices that are not soldered and sealed with an adhesive heat shrink or epoxy
resin, replace the splice with one that is. Using a MegOhm meter, measure the resistance from one of the loop
wires to earth ground. It should be greater than 50 megohms. Inspect the loop. Look for exposed wires or debris
pressed into the saw cut. Tighten all screw terminals in the signal cabinet that the loop circuit uses. Check solder
joints in the loop circuit, especially on the rack itself. Disconnect and reconnect any connector used in the loop
circuit and check for loose pins and sockets in these connectors. I f your cabinet has lightning or sur ge suppress ion
devices on the loop inputs in the cabinet, remove or replace them. Check for places in the field where the loop
wire or lead-in cable may be pinched or chaffed. Look for wires pinched under junction bo x covers a nd where the
wire enters a conduit, especially where the loop wire leaves the saw cut and enters a conduit. After checking all of
the above items, you could swap out the detector but this type of failure is rarely ever related to the detector.
8.4 TROUBLESHOOTING INTERMITT EN T D ET EC TO R LOCK-UPS
Problems of this type tend to be difficult to isola te due to the many possible causes and the short duration of the
symptom (usually less than 30 minutes). If the proble m occurs more frequently in t he morning or when raining,
suspect a short to earth ground in the loop / lead-in circuit. This can usually be ve r ified by testing with a MegOhm
meter, but not always. Vibration can also be a possible cause. Loop wires may be moving slightly in a conduit due
to vibrations from truck traffic. Utility lids in t he street near t he loop may also be a source o f problems. E nsure
that lids near a loop are bolted down so that they cannot move. Check that each set of loop wires is twisted
together in any pull boxes and that lengths are not excessive. Inspect the loop. Look for exposed wires or debris
pressed into the saw cut. Check for places in the field where the loop wire or lead-in cable may b e pinc hed or
chaffed. Look for wires pinched under junction box covers and where the wire enters a conduit, especially where
the loop wire leaves the saw cut and enters a conduit. If your cabinet has lightning or surge suppression
devices on the loop inputs in the c abinet, remove or replace them. If you have any splices that are not soldered
and sealed with an adhesive heat shrink or epoxy resin, replace the splice with one tha t is. S older all cr imp
connections in the loop circuit. Tighten all screw termina ls in the signal cab inet that the loop circ uit uses. C heck
solder joints in the loop circuit, especially on the harness itself. Disconnect and reconnect any connector used in
the loop circuit and check for loose pins and sockets in these connectors.
8.5 TEST MODE OPERATION
Test Mode uses the microcontroller to verify the proper operation of the detector’s controls and indicators
(switches and LEDs). The detector’s loop oscillator circuit is also checked to verify the correct frequency in each
of the fou r fre que nc y se lections. The frequency portion o f the test req uires the detector to be connected to a 100
micro henry loo p. If an ind uctance value ot her than 10 0 micro henries is used, the freque ncy test r esults w ill be
invalid.
NOTE: The test procedures outlined below should not be performed in an operational traffic signal cabinet.
Test Procedure (Programming DIP switches):
S
TEP 1. Remove power from the detector.
S
TEP 2. Set all front panel Programming DIP switc hes (S1) to the OFF position.
S
TEP 3. Set all front panel Delay / Extension DI P s witches (S2) to the OFF position.
S
TEP 4. Install a two-pin shorting jumper (shunt) to the PC Board mounted header labeled TEST (JP1) and
apply power. The LED indicator should be OFF, all detect outputs should be OFF. NOTE: To
test the frequency range the detector must be connected to a 100 microhenry loop. The other
tests may be performed with loops within the range of 20 to 2000 microhenries.
S
TEP 5. Indivi dually, t urn ON sw itches 6, 5, 4, and 3 o f the Pro gramming DIP switch. Turn OFF each
switch after verifying the results ind icated in the table below.
STEP 6. Remove power from the detector and remove the two-pin shorting jumper from the TEST header.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 17 of 20
Switch Label
Switch #
LED Indications and Outputs
FREQ 1
2
DETECT / FAIL LED ILLUMINATED - GREEN
FREQ 2
1
DETECT / FAIL LED ILLUMINATED - RED
Switch Label
Switch #
LED Indications and Outputs
DELAY 32
12
DETECT / FAIL LED ILLUMINATED - GREEN
DELAY 16
11
DETECT / FAIL LED ILLUMINATED - RED
DELAY 8
10
DETECT / FAIL LED ILLUMINATED - GREEN
DELAY 4
9
DETECT / FAIL LED ILLUMINATED - RED
DELAY 2
8
DETECT / FAIL LED ILLUMINATED - GREEN
DELAY 1
7
DETECT / FAIL LED ILLUMINATED - RED
EXTEND 8
6
DETECT / FAIL LED ILLUMINATED - GREEN
EXTEND 4
5
DETECT / FAIL LED ILLUMINATED - RED
EXTEND 2
4
DETECT / FAIL LED ILLUMINATED - GREEN
EXTEND 1
3
DETECT / FAIL LED ILLUMINATED - RED
EXTEND 1/2
2
DETECT / FAIL LED ILLUMINATED - GREEN
EXTEND 1/4
1
DETECT / FAIL LED ILLUMINATED - RED
Action
LED Indications and Outputs
• DETECT / FAIL LED ILLUMINATED - ORANGE
• BUZZER SOUNDS
• DETECT / FAIL LED OFF
• BUZZER OFF
Test Procedure (Frequency DIP switches):
STEP 1. Remove power from the detector.
S
TEP 2. Set all front panel Programming DIP switc hes (S1) to the OFF position.
S
TEP 3. Set all front panel Delay / Extension DI P s witches (S2) to the OFF position.
S
TEP 4. Install a two-pin shorting ju mper (shunt) to the PC Board mounted header labeled TEST (JP1) and
S
TEP 5. Indivi dua lly, tur n ON the t wo Freq ue ncy D IP s witc hes (sw itc hes 2 and 1 of t he P rog ra mmin g DIP
STEP 6. Remove power from the detector and remove the two-pin s horting ju mper fro m the
TEST header.
An LED i nd icat ion d iffe re nt t han t he o nes des cribe d for ea ch s wit ch s ett ing indic at es t he lo op freq uenc y is out of
tolerance. Verify that the loop test coil has an inductance of 100 microhenries. If the test loop measures 100
microhenries the detector module should be serviced.
Test Procedure (Delay / Extension DIP switches):
S
TEP 1. Remove power from the detector.
S
TEP 2. Set all front panel Programming DIP switc hes (S1) to the OFF position.
S
TEP 3. Set all front panel Delay / Extension DI P s witches (S2) to the OFF position.
S
TEP 4. Install a two-pin shorting jumper (shunt) to the PC Board mounted header labeled TEST (JP1) and
S
TEP 5. Individually, turn ON switches 12 t hrough 1 o f the Delay / Extension DIP switch. T urn OFF eac h
apply power. The LED indicator should be OFF, all detect outputs should be OFF. NOTE: To
test the frequency range the detector must be connected to a 100 microhenry loop.
switch). Turn OFF each switch after verifying the results indicated in the table below.
apply power. The LED indicator should be OFF, all detect outputs should be OFF. NOTE: To
test the frequency range the detector must be connected to a 100 microhenry loop. The other
tests may be performed with loops within the range of 20 to 2000 microhenries.
switch after verifying the results ind icated in the table below.
STEP 6. Remove power from the detector and remove the two-pin shorting jumper from the TEST header.
Test Procedure (Front Panel Buzzer switch):
TEP 1. Remove power from the detector.
S
S
TEP 2. Refer to the table in Section 3.5 and set all front panel Pro gramming DIP switches (S1) to their
default positions.
S
TEP 3. Set all front panel Delay / Extension DI P s witches (S2) to the OFF position.
S
TEP 4. Apply power. The LED indicator should be OFF, all detect outp uts should be OFF. NOTE: To
test the frequency range the detector must be connected to a 100 microhenry loop. The other
tests may be performed with loops within the range of 20 to 2000 microhenries.
S
TEP 5. Press the Front Panel mounted s witch labeled BUZZER. The buzzer should sound once (50 ms).
S
TEP 6. Perform the actions and verify the results indicated in the table below.
INPUT CALL
REMOVE CALL
STEP 7. Press the Front Panel mounted sw itch labe le d BUZZER. The buzzer should sound once (250 ms).
S
TEP 8. Remove power from the detector.
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 18 of 20
Switch / Button / Input
Action
LED Indications and Outputs
DETECTOR RESET
BUTTON
• DETECTOR OUTPUT ON
• TEST BOX CHANNEL 1 DETECT LED ON
DETECTOR RESET
BUTTON
• DETECTOR OUTPUT OFF
• TEST BOX CHANNEL 1 DETECT LED OFF
Test Procedure (Front Panel Reset switch):
STEP 1. Remove power from the detector.
S
TEP 2. Refer to the table in Section 3.5 and set all front panel Pro gramming DIP switches (S1) to their
default positions.
S
TEP 3. Set all front panel Delay / Extension DI P s witches (S2) to the OFF position.
S
TEP 4. Apply power. The LED indicator should be OFF, all detect outputs should be OFF. NOTE: To
test the frequency range the detector must be connected to a 100 microhenry loop. The other
tests may be performed with loops within the range of 20 to 2000 microhenries.
S
TEP 5. Perform the actions and verify the results indicated in the table below. NOTE: Unless otherwise
noted, references to switches, buttons, or inputs in the table correspond to labels on test equipment
supplied by Re no A & E.
PRESS AND HOLD
RELEASE
STEP 6. Remove power from the detector.
8.6 THINGS TO KNOW ABOUT LOOPS
Always use a wire with cross-linked Polyet hylene insu lation (insulation type XLPE) for loo p wire.
Typical sensing height is ⅔ of the shortest leg of a loop. Therefore, a 6΄ x 6΄ loop will have a detection height of 4΄.
The inductance of a conventional four-sided loop can be estimated using the formula:
L = P x (T2 + T) / 4 Where: L = Loop Inductance in microhenries
P = Loop Perimeter in feet
T = Number of Turns of Wire.
Therefore, a 6΄ by 6΄ loop with 3 turns would have an inductance of:
L = (6 + 6 + 6 + 6) x (32 + 3) / 4
L = 24 x (9 + 3) / 4
L = 24 x 12 / 4
L = 24 x 3
L = 72 microhenries.
The inductance of a QuadrupoleTM loop can be estimated using the formula:
L = [P x (T2 + T) / 4] + [CL x (T2 + T) / 4] Where: L = Loop Inductance in microhenr ie s
P = Loop Perimeter in feet
T = Number of Turns of Wire
CL = Length of Center Leg in feet.
Therefore, a 6΄ by 50΄ loop with a 2-4-2 configuration would have an ind uctance of:
L = [(6 + 50 + 6 + 50) x (22 + 2) / 4] + [50 x (42 + 4) / 4]
L = [112 x (4 + 2) / 4] + [50 x (16 + 4) / 4]
L = (112 x 6 / 4) + (50 x 20 / 4)
L = (112 x 1.5) + (50 x 5)
L = 168 + 250
L = 418 micr ohenries.
Loop Feeder cable typically adds 0.22 microhenrie s of inductance per foot of cable.
Total inductance of loops connected in series: L
Total inductance of loops connected in parallel: L
= L1 + L2 + L3 + . . . + LN.
TOTAL
= 1 / [ (1 / L1) + (1 / L2) + (1 / L3) + . . . + (1 / LN) ].
TOTAL
889-2008-01 Model T-110 Operations Manual Rev Apr 2020 Page 19 of 20
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