8.7 Things to Know About Loops .................................................................................26
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Section 1 General Description
This product manual was written for people installing, operating, a nd maintaining the R eno A & E Model U-1000
Series inductive loop vehicle detector. The Model U-1000 Series consists of two versions. The Model U-1200 is a
four c ha n ne l, shelf mount t ype inductive lo op vehic le detector des igned to meet or excee d NEMA Standards T S 1-
1989. The Model U-1100 is a four channel, s helf mount t ype ind uctive loop vehic le dete ctor des igned specifica lly
to conform to the specifications s et forth in paragraph 86-5.01A (3b) of the 1981 version o f the Caltrans Standard
Specifications.
A front panel mounted, 4 pin, circular pla stic connector and 10 foot wiring harness have bee n included with the
Model U-1000 detector to support Phase Green Inputs (Delay ove rr ides) for each channel. These inputs are used to
control delay timing, phase green loop compensation, end-of-green, third car passage or detector disconnects. If
these functions are required and cannot be accomplished satisfactorily through the controller, appropriate
connection of the wiring harness will allow the detector to perform them.
The Model U-1000 uses a microcontroller to monitor and process signals from the loop / lead-in circ uits, Phase
Green I nputs, and t he reset inp ut. It uses these input s to determine how to control the four detector channel
outputs. A Liquid Crystal Display (LCD ), four light e mitting diodes ( LEDs), and four fro nt panel pushb uttons are
used to display and program all detector functions. Several diagnost ic modes are available to aid technicians and
service personnel in troubleshooting detection problems.
The use of a LCD is what distinguishes this detector from that of other manufacturers. It allows more informat ion,
never before available, to be displayed to the user during normal operation of the detector. The LCD makes it easy
to view and adjust all programmable detector opt ions and settings. It is no longer necessary to check o r change
detector settings with DIP sw itches. An eight-segment bargraph at the top of the L CD can be used to provide a
graphical representation of the relative change of inductance as seen by the detector at the current sensitivity level.
The bargraph automatically takes into account loop size, loop inductance, nu mber of loops, number of turns, loop
geometry, lead-in length, etc. The bargraph functions as a sliding scale that relates to the programmed Sensitivity
Level. The first (left-most) bargraph segment represents the minimum inductance change necessary for the
detector to output a call at the currently selected sensitivity level. Larger inductance changes will indicate more
segments. Each additional segment indicates that the next sensitivity level has also been met or exceeded. When
used in t his manne r, the bar graph prov ides an ind ication of whether the sensitivity is set too high or too low,
facilitating the ideal setting of the se ns itivity level.
All programmed settings are stored in non-volatile memory and can only be changed by programming new
settings. Loss of power or a detector reset will not change any of t he programmed settings. If a loop failure
occurs, the LCD will display the type of lo op failure as L lo (for -25% change or s horted loop conditions) or L hi
(for +25% change or open loop c onditions). Each loop failure is co unted and accumulated in the Loop Failure
Memory. The number of failures since the las t detector reset or power interruption is very useful information
during analysis of intermittent loop operation.
The Model U-1000 Series detector is a scanning detector. The scanning operation sequentially activates the ON
and OFF cycle of each channel’s oscillator. Since only one channel’s loop(s) is (are) active at a given time,
crosstalk between adjacent loops connected to the same scanning detector is minimized. The Model U-1000
Series’ unique scanning process also disconnects the capacitors and dampens the oscillator during the off cycle.
This eliminates oscillation past the OFF point (ringing or deca y) every time the loop circuit is scanned which can
result in crosstalk.
When operating in the Program Mode, the Model U-1 000 Series d isplays the rea l time loop frequency reading for
each channel. The eight frequency settings can be incremented or decremented to provide precise frequency
readings, removing any guesswork w hen changing frequency settings to eliminate cros stalk. NOTE: Adjacent
loops connected to different channels of a non-sc anning detector or different scanning dete ctors should be set to
different frequencies with maximum separation.
The Re no A & E M odel U-1000 Series utilizes the first major innovat ion in inductive loop detectors since the
introduction of digital detecto rs. The programming of all of the detector’s para meters with four normally open
pushbutton switches not o nly simplifies setup by removing binary coded DIP switches, but also increases the
reliability of the detector by eliminating the dependence on switch contacts during normal operation. The detailed
descriptions displayed on the LCD eliminate the interpretation of numerous LED flash rates to determine the
detector status. In addition, the Mode l U-1000 offers the ve rsatility of softwa re control. Spec ial functions are
possible with a simple change of the socket-mounted microprocessor. Special functions are de fined as unique
options (e.g. Option 5, Opt ion 12, etc.). Spe cial option functio ns are activated thro ugh the use of t he LCD menu
option programming.
The Model U-1000 Series is comprised of the following detectors:
U-1100-R For retrofit applications ca lling for a four channel, shelf mount detecto r with
relay outputs and an audible detect signal (buzzer) conforming to the
specifications set forth in paragraph 86-5.01A (3b) of the Caltrans Standard
Specifications.
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U-1100-SS For retrofit applications ca lling for a four channel, shelf mount detecto r with
U-1200-R For NEMA TS 1-1989 applications calling for a four channel, shelf mount
U-1200-SS For NEMA TS 1-1989 applications calling for a four channel, shelf mount
solid state outputs and an audible detect signal (buzzer) conforming to the
specifications set forth in paragraph 86-5.01A (3b) of the Caltrans Standard
Specifications.
detector with relay outputs and an audible detect signal (buzzer).
detector with solid state outputs and an audible detect signal (buzzer).
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Section 2 General Characteristics
2.1 LOOP FREQUENCY
There are eight (8) selectable loop frequency settings (nor mally in the range of 20 to 100 kilohertz) per c hannel.
The actual loop operating frequency is a function of the loop / lead-in network and the components of the loop
oscillator circuit. The d igital display of the actual loop operating frequency for each setting makes it easy to
quickly identify and eliminate crossta lk in the most difficult to configure intersections. The frequency display is
typica lly very stab le when the loop is vacant and veh icles are not passing nearby the loops. If the reading is
varyin g by more than ±1 in the last digit, this is an indication of possible crossta lk betwee n loops.
2.2 SENSITIVITY
There are nine (9) selectable sensitivity levels per channel, plus Continuous-Call and Cha nne l-O f f. T he s ensitiv i t y
levels are designed so that a one level increase actually doubles the sensitivity and a one level decrease halves the
sensitivity. A unique bargraph d isplayed on t he LCD makes it eas y to quickly set sensitivity at t he ideal leve l for
any loop / lead-in network configuration. (See Section 3.4 fo r actual detection levels at each sensitivity level.)
C
ONTINUOUS-CALL: Whe n se t t o t he Co nt in uo us -Call state , the c hannel ou tput is co ntinuous ly in t he Call state
regardless of t he presence or absence of vehicles o ver the loop. The loop oscillator is d isabled when in the
Continuous-Call state. T his state is indicated b y CALL flashing on the LCD. This option is selected from the
Sensitivity menu in Program Mode and is useful for checking co ntroller response and other troubleshooting
activities.
C
HANNEL-OFF: When s et to the Channel-O ff state, the channel output is cont inuously in the No Call state
regardless of the presence or absence of vehicles over the loop. The loop oscillator is disabled when in the
Channel-Off State. This sta te is indicated by OFF flashing on t he LCD. This option is selected from the
Sensitivity menu in Program Mode and is useful for checking co ntroller response and other troubleshooting
activities.
2.3 PRESENCE / PULSE
One of two mutually exclusive modes of operation for each channel is available. Presence or Pulse mode is
toggled by momentarily pressing e ither the (UP) or (DOWN) button.
P
RESENCE MODE: Provides a call hold time of at least four min utes (regardless of vehicle size) and typically one
to three hours for an automobile or truck.
P
ULSE MODE: An output Pulse of 125 ±10 milliseconds duration is generated for each vehicle entering the loop
detection zone. Each detected vehicle is instantly tuned out if it remains in the loop detection zone longer than
two seconds. This enables detection of subsequent vehicles entering the loop detection zone. After each vehicle
leaves the loop detection zone, the channel resumes full sensitivity within 0.5 seconds.
2.4 CALL DELAY
Each channel’s Call Delay is ad justab le from 0 t o 255 seconds in one-second steps. Call Delay time starts counting
down when a vehicle enters the loop detection zo ne. The remaining Ca ll Delay time i s continuous ly displayed on
the LCD . W he ne ver a Pha se Gr ee n I npu t ( Ca ll D e la y Ove r rid e ) s ig nal ( p in 1 , 2 , 3 , o r 4 o f t he 4-pin connector) is
active, the Call Delay function for the channel is aborted and the Call Delay time is forced to zero.
2.5 CALL EXTENSION
Each c hannel’ s Call Ext ension is adjustable from 0 to 25.5 seconds in 0.1-second steps . Extension time starts
counting down when the last vehicle clears the loop detection zone. The remaining Call Extension time is
contin uous ly d isp la yed o n the LCD. Any veh icle ente r ing t he lo op de tec tio n zo ne d uri ng t he Ca ll E xtens io n ti me
period causes the channel to return to the Detect state, and later, when the last vehicle clears the loop detection
zone, the full Call Exte nsion time starts counting down again. (See Option 3, Call Extension Control, for an
alternate mode of operation for Call Extension.)
2.6 MAX PRESENCE TIMER
When activated, each channel’s Max Presence timer is adjustable from 1 to 999 seconds in one-second steps. A
setting of OFF turns the Max Presence timer off. The Max Presence function is used to limit prese nce time, by
automatically resetting the channel. If this function is enabled (ON), the Max Pre sence timer begins counting
down when a call is initiated and t he remaining ti me is continuously displaye d on the LCD. If t he loop becomes
vacant before the Max Presence timer reaches zero, the call is dropped and no automatic reset occurs. If the EndOf-Green (EOG) function is not enabled (OFF) and the call is still present when the Max Presence timer reaches
zero, the cha nnel then is aut omatically reset. If the EOG function is enabled (ON) and the call is s till present when
the Max Presence timer reaches zero, the channel enters a Wait state. The Wait state continues until either the loop
becomes vacant or the Phase Green Input signal for a channel (pin 1, 2, 3, or 4 of the 4-pin con nec tor ) tra ns itio ns
from green to not green with t he call still present. If the loop be comes vacant first, the call is dro pped and no
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automatic reset occurs. If the Phase Green Input transitions from green to not green while a channel is in a Wait
state, the channel is automatically reset. The signals on pins 1, 2, 3, and 4 of the 4-pin connector are also called
Call Delay Overrides. (See Section 3.2, Phase Green Input specification for voltage levels.)
2.7 END-OF-GREEN (EOG)
Each channel’s EOG setting can be toggled O N or OFF b y moment arily pr essing either the (UP) or (DOWN)
button. The EOG function is used to synchronize resetting of a detector with the termination of the associated
phase green. The assumption is that this is t he safest point in t ime to reset t he channel. T his assumpt ion is based
on the premise that at the termination of the associated phase green, traffic should be moving, and therefore, a reset
would not result in the loss of a call w hen traffic comes to rest over the loop(s). The EOG function is only
available when the Max Presence function is set between 1 and 999 seconds. It is not available when the Max
Prese nce fun ct io n is O FF. W he n t he E OG func t io n is ena b led (ON ), t he channel will automatica lly be reset at the
same time the Phase Green Input s ignal (pin 1, 2, 3, o r 4 of the 4-p in connector) transitions from the ON state to
the OFF state, if the Max Presence Time has counted down to zero and is resting in the wait state. The s ig nals o n
pins 1, 2, 3, and 4 of the 4-pin connector are also called Call Delay Overrides. (See Section 3.2, Phase Green Input
specifications for voltage levels.)
2.8 OPTION 1: LOOP INDUCTANCE DISPLAY
Each channel’s Loop Inductance Display setting can be toggled ON or OFF by momentarily pressing either the
(UP) or (DO W N ) b u t to n. W hen this option is e na b le d (ON), t he LCD d is p lays the to t al lo o p i nd uc t a nc e (a c t ua l
loop inductance plus actual lead-in inductanc e) in micro henrie s for loop in ductanc e values in the ra nge of 20 to
2500 microhenries. By recording the inductance of the loop / lead-in circuit when it is first insta lled, the actual
inductance can be compared to the expected inductance to help identify defective loop / lead-in circuits. Loop /
lead-in inductance can be easily estimated using the simple formulas included in Section 8.7 of this manual.
NOTE: Enabling this option act ivates it for all c hannels. This option is auto matically disabled 15 minutes after
activation or on loss of power.
2.9 OPTION 2: LOOP INDUCTANCE -∆L/L DISPLAY
Each cha n ne l’s Loo p I nd uct a nce -∆L/L Display sett ing can be toggled ON or OFF by momentarily press ing either
the (U P) or (DOWN ) button. Wh en this option is enab led (ON), the LCD dis plays the pe rcentage of
inductanc e change ( -∆L/L value) during the Call state. To facilitate t he viewing of the maximum amount of
change in the -∆L/L value while traffic is in motion over the detection zone, the channel holds the peak -∆L/L
value for a period of two seconds. NOT E: Enabling this option activates it for all channels. This option is
automatically disabled 15 minutes after activation or on loss of power.
2.10 OPTION 3: CALL EXTENSION CONTROL
Each cha nnel’ s Cal l Exte nsion C ontro l set ting ca n be to ggled O N or OF F by mo mentar ily pre ssin g eithe r the
(UP) or (DO WN ) b ut to n. W he n t h is o pt io n is e nab led (O N) , t he c ha n nel w ill e x tend ca l ls f or t he pr o gra mme d
extens ion ti me only when t he P hase Gr ee n Inp ut s ign al ( pi n 1, 2 , 3, or 4 of the 4 -pin connector ) is active. When
this o pt ion is OF F, t he channe l extends A L L c alls for t he p r o grammed e xt e nsion t ime . The si g na ls o n pins 1, 2 , 3,
and 4 of the 4-pin connector are also called Call Delay Overrides. (See Section 3.2, Phase Green Input
specifications for voltage levels.)
2.11 OPTION 4: NOISE FILTER DISABLE
The detector’s Noise Filter Disable setting can be toggled ON or OFF by momentarily pressing either the (UP)
or ( DO WN ) b utt o n. W he n Op t io n 4 is e nab le d ( ON ), inte r na l no is e f ilt er in g is d isa ble d t hus p ro vid in g a fas te r
response time. When this option is O FF, internal noise filtering is utilized. W hen the detector is used in speed
and/or occ upa ncy a pp lica tio ns, the noise filter should be disabled (i.e. Option 4 ON ) to provide the most acc urate
data possible. It is recommended t hat this option not be activated. The factory default setting o f OFF provides
stable operation in high crosstalk environments. NOTE: Enabling this option activates it for all channels.
Changing the setting of this feature will reset all detector channels.
The Loop Fail Count is not reset when the setting of Option 4 is changed. Also, changing the setting of Option 4
will not cause the prior Loop Fail indication to cease (see Section 5.3, Loop Fail Indications).
2.12 OPTION 5: PHASE GREEN LOOP COMPENSATION
Each channel’s Phase Green Loop Co mpensation setting can be toggled ON or OFF by mo mentarily pressing
either the (UP) o r (DOWN) button. W hen Option 5 is enabled (ON), normal loop compensation is used until
the Phase Green Input signal (p in 1, 2, 3, or 4 of the 4-pin connector) becomes active. Once the Phase Green Input
signal is active, the channel desensitizes the loop. Maximum desensitization is 0.05% (-∆L/L). This
desensitization tunes out small changes, such as adjacent lane pickup, therefore minimizing the chance of max
timing an empty lane. Note: A small motorcycle may also be tuned out in a short period of time follow ing the
start of Phase Green. This option is useful in minimizing false detectio n resulting from adjace nt lane pickup when
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Loop B
Loop A
a channel must be run with a high sensitivity setting. When Option 5 is not enabled (OFF), normal loop
compensation is use d.
2.13 OPTION 9: THIRD CAR PASSAGE
Each channel’s Third Car Passage setting can be toggled ON or OFF by momentarily pressing either the (UP) or
(DO WN ) b ut to n. O p tio n 9 is a p a ire d cha nne l opt io n. Th is me ans t hat it ta ke s t w o c ha nne ls to imp le me nt the
feature. Therefore, when this option is toggled ON or OFF in one channel, its paired channel is also set to the same
state. In the Model U-1000, Channel 1 is paired with Channel 2 and Channel 3 is paired with Cha nnel 4. NOTE:
Optio n 9 is mut ually e xclusive with Op tion 10 . Turning ON one option will auto matically turn OFF the other
option.
When Op t ion 9 is e nab led (ON ) , t he o utp u t o f the tw o pa ir ed c ha n ne ls a re log ic a lly AND ed t o get he r. Th is mea ns
that while the loops for both of the paired channels are occupied, a call will be output on both channels. While
only one channel is occupied, or neither channel is occupied, a call will not be output for either cha nnel. The first
channel with detection will enter a pending state while waiting for detection on the other paired channel. While in
the pending state, the LCD will show Pnd on the d isplay.
This feature is intended to be used in Protected / Permissive left turn situations. The expected installation is a stop
bar loop for the left turn lane connected to one channel, a queue detection loop (with a small amount of delay time
programmed) for the left turn lane connected to the other channel, and the output of eithe r channel conne cted to the
Vehicle Call input for the protected movement of the traffic controller.
Basic Installation - Loop A is the Queue
Detection loop and Loop B is the Stop Bar
loop.
Car enters Loop A - No call is output.
Car proceeds to Loop B - No call is output.
Additional cars enter the left turn lane - When
the back of the queue reaches Loop A while a
car is still over Loop B, a call will be output.
When T hird Car P assage is turned o n, as the fi rst vehi cle enter s the left turn lane it will d rive ove r the queue
detection loop. Since there is no vehic le over the stop bar loop, there is no call ou tput ge nerate d. The vehic le
advances to the stop bar loop. Still, no output is generated because there is no vehicle over the queue detection
loop. If the vehicle traffic in the left turn lane backs up to the queue detection loop, then the stop bar loop and t he
queue detection loop will both be occupied at the same time. This will cause the detector to generate a call to the
traffic controller to service the protected movement for the left turn. This should help clear the queue of vehicles
in the le ft turn lane. The spacing between the stop bar loop and the queue detectio n loop controls the size of the
queue needed to generate a call to the protected movement of the controller. The delay time on the Queue
Detection loop should be sufficiently long that vehic les driving over this loop to enter the queue do not ge nerate a
call.
2.14 OPTION 10: DIRECTIONAL LOGIC
Each channel’s Directional Logic setting can be toggled ON or OFF by momentarily pressing either t he (UP) or
(DOWN) button. Option 10 is a paired c hannel option. This means that it takes two channe ls to implement t he
feature. Therefore, when this option is toggled ON or OFF in one channel, its paired channe l is a lso set to the sa me
state. In the Model U-1000, Channel 1 is paired with Channel 2 and C hannel 3 is paired with Channe l 4. NOTE:
Option 10 is mutually exclusive with Opt ion 9. Turning ON one option will automatically tur n OFF the other
option.
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Loop B
Loop A
When Option 10 is enabled (ON), directional logic is enabled. Directional logic starts with a detect ion on one
channel. This channel will go into the pending state, display Pnd on the LC D , a nd N O T output a c a l l. W hen both
of the paired channels have detection, the last c ha nne l to have detection will output a call until the detection for the
last cha n ne l ends, even if th e de t ec t ion end s for the f ir s t channe l. N o ne o f t he t i mi n g f u nc t io ns of the f ir s t channe l
with a detection will ti me (Delay, Extens ion, Max Presence, a nd Detector Disconnect) a nd the first channel w ill
always operate in the Presence Mode regardless of the programming of the channel.
This feature is intended to be used in parking lot applications where vehicles can enter or exit from the same lane,
freewa y ra mp s for wro ng w a y de tec t ion, a nd le ft t urn lane s whe re ot her mo ve men ts in the intersec tion te nd to clip
the detection zone of the left turn lane. The expected installation is two loops, one after the other in the same lane,
spaced anywhere from slightly overlapping to 6 feet apart. NOTE: Contact a Field Engineer at Reno A & E regarding proper loop configurations and spacing for specific applic ati ons.
When Directional Detect ion is turned on, a vehicle entering the first loop will cause that channel to enter t he
pending state. As the vehicle enters the second loop w hile still occupying the first loop, the second channel will
enter the Call state while the firs t channe l remains in t he pending s tate. A ca ll is never outp ut on the first c hannel
with a detection. Under normal conditions both outputs can never be on at the same time. However, if one of the
loops fail, both outputs will come on and stay on until the failure is corrected.
Basic Installation
Car enters Loop A - No call is output Car enters Loop B - No call is output
Car proceeds to Loop B Car proceeds to Loop A
Call is output on Chan nel B Call is output on Channel A
2.15 OPTION 11: AUDIBLE DETECT SIGNAL
Each c hanne l’s, A udible Detec t Sig nal set ting c an be t oggled ON or OFF b y mome ntar ily pre ssing e ither the
(UP) or (DOWN) butto n. Only one channel can be turned ON at a time. Turning this option ON for one
channel auto matically turns it OFF for the other channels. W hen this o ption is enable d (ON), a n audible signal will
be activated whenever the detection zone for the selected channel is occupied. The audible signal indicates actual
occupancy of the loop detection zone. Timing a nd disconnect functio ns have no e ffect on t he audible s ignal. This
feature allows a technician to watch the detection zone on the street and confirm correct detector operation without
having to look at the detector display as well. NOTE: This option is auto matically disabled 15 minutes after
activation or on loss of power.
2.16 OPTION 12: DETECTOR DISCONNECT
Each channel’s Detector Disconnect setting can be toggled ON or O FF and the Extension ti mer toggled between
ON and OFF by momenta r il y pr es sing ei t h er t he (UP) or (DOWN) button. The Detector Disconnect feature
requires that the Phase Green Input for the channel be connected to the proper controller phase. When the Phase
Green I nput is no t a c t i ve , t he c hannel s hall ope ra te no r mally. W hen the P ha s e Gr e e n I np ut is a c t iv e , t he e xt e nsion
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Detection Zone
Phase Green
Output w/ 12.1 Off
Output w/ 12.1 On
This example assumes an extension time of 2 seconds. The dott ed lines show where disconnect would occur.
Seconds 0 5 10 15 20 25 30 35 40 45 50 55
timer will start to count down at the end of each detection. If this timer reaches zero before the next detection, this
channel will no longer output a call until the Phase Green Input is not active. Since the extension timer is used as a
disconnect timer while in this mode, two different disconnect types are available:
Option 12.1 OFF: Extension timing still occurs and the extens ion timer is also the disc onnect timer du ring phase
green. This will cause the call output to re main in the Call state until disconnect oc curs. This may allow the
user to use gap times appropriate for the advance loops without considering the effects on the stop bar loops.
Option 12.1 ON: E xte ns ion timing is disabled and the extension timer is used as the disconnect timer. T his will
cause the call output to follow the occupation of the loop detection zone until disconnect occurs.
This feature is intended to be used in applications where a loop at the stop ba r is not needed after any waiting
queue in the associated traffic lane is movi ng during t he green p hase. The e xpected insta llation is a sto p bar loop
(typically a 20΄ to 30΄ long detection zone) and an advance detection loop (typically a 6΄ long detection zone) for a
single traffic lane. This feature provides a means for keeping the stop bar loop from placing ca lls to the traffic
controller after the stop bar loop has served its intended purpose during the beginning period of the associated
green phase. The channel connected to the stop bar loop would have the Detector Disconnect feature turned ON
and have a programmed extension time that functions as the disconnect time. The channel connected to the
advance detection loop would be programmed as normal.
When the Detector Disconnect feature is turned ON and the signal is not green, the channel outputs calls to the
traffic controller as usual. W hen the signa l turns gree n, vehicles begin to move and eventually the stop ba r
detection zone is cleared. At the time that the stop bar detection zone is cleared the disconnect timer begins to
Phase Green is the state of the light (actual Phase Green Input is inverted).
count down. If another vehicle enters the stop bar detection zone before the disconnect timer reaches zero, the
channel outputs the new call to the traffic controller and the disconnect timer is reset to its initial value. Once the
stop bar detection zone remains clear for a time equal to the programmed disconnect time, the detector channel is
disabled and will not generate any further calls to the traffic controller until after the green has terminated. When
the stop bar detection loop is disabled, the green phase can only be extended by vehicles detected by the advance
detection loop. NOTE: The disconnect timer will always time an initial gap each time that the phase turns green.
If Option 12.1 is OFF, the cha nnel will generate an o utput fo r the specified extension time at the start of each green
phase.
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Section 3 Specifications
3.1 PHYSICAL
WEIGHT: 34 oz. (964 gm).
S
IZE: 6.40 inches (16.25 c m) high x 2.48 inches (6.30 cm) wide x 6.38 inches (16.19 cm) long (excluding
connectors). Connectors add .675 inch (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 polyuretha ne.
C
ONNECTORS: MS3102A-22-14P, 19 pin male. See section 3.6 for pin assignments.
POWER: 89 to 135 VAC, 50/60 Hz, 6 Watts maximum.
L
OOP INDUCTANCE RANGE: 20 to 2500 microhenries with a Q factor of 5 or greater.
L
OOP INPUTS: Transformer isolated. The minimum capacitance added is 0.068 microfarad.
L
IGHTNING PROTECTION: Meets and/or exceeds all applicable NEMA TS 1-1989 specifications for transient
voltage protection. Each channel can tolera te, without damage, a 10 microfarad c apacitor charged to 2,000 volts
being discharged directly into the loop input terminals, or a 10 microfarad capacitor charged to 2,000 volts bein g
discharged between either loop terminal and earth ground.
R
ESET: Meets and/or exceeds NEMA TS 1-1989 detector specificat ions. The detector can be reset by re moving
and reapplying power or by changing the setting of Option 4 (Noise Filter Disab le). Each detector channel can be
independently reset by pressing the CHAN button until the desired c hannel is selected, then pressing and ho lding
the CHA N b ut t o n fo r t hr e e se c o nd s . A ls o, c ha n gi n g either the sensitivit y or loop fr e q uency o f a channe l will res e t
that channel.
P
HASE GREEN INPUTS: Also known as Call Delay Overrides. Meets and/or exceeds all NEMA TS 1-1989
requirements. Application of a high state volta ge (89 to 135 V AC) to p in 1 (C h. 1) and/or pin 2 (C h. 2) a nd/or pin
3 (Ch. 3) and/or pin 4 (Ch. 4) of the 4-p in connector causes the delay timer for the channel to abort the delay
timing function and also pro vides control for Phase Green Loop C ompensation, Max Presence Ti ming (End-ofGreen), Extension timing, and Detector Disconnect, if the features are programmed.
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 current. 2 VDC maxi mum t rans istor sat urat ion vo lta ge. The o utp ut is p rote cted w it h a
33-volt Zener diode connected between the collector (drain) and emitter (source).
3.3 OPERATIONAL
DISPLAY:The LCD backlighting illuminates whenever any pushbutton is pressed. The backlighting will
extinguish 15 minutes after the last pushbutton press.
D
ETECT INDICATOR: Each channel has a super bright, high intensity, red light e mitting diode (LE D) to indicate a
Call Output, Delay Timing, Extension Timing, Pending State, or Failed Loop co ndition.
R
ESPONSE TIME: Meets or exceeds NEMA TS 1-1989 response time specifications. (See Section 3.4 for actual
response times.)
S
ELF-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 loop isolatio n transformer allows operation 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.
L
OOP (FAIL)MONITOR: If the to ta l in d ucta nc e o f t he c han ne l’s lo op in put ne tw or k goe s out o f t he ra n ge s pec i fied
for the detector, or rapidly changes by more than ±25 %, the channel will immediate ly e nte r t he Fail-Safe mode and
889-2103-01 Model U-1000 Operations Manual Page 8 of 26
Page 15
Respons e Time
(Option 4 O FF)
Respons e Time
(Option 4 ON)
OFF
-------
-------
-------
1
0.64%
160 ±50 ms
35 ±7 ms
2
0.32%
160 ±50 ms
35 ±7 ms
3
0.16%
160 ±50 ms
35 ±7 ms
4
0.08%
160 ±50 ms
35 ±7 ms
5
0.04%
160 ±50 ms
35 ±7 ms
6
0.02%
160 ±50 ms
48 ±10 ms
7
0.01%
160 ±50 ms
79 ±17 ms
8
0.005%
160 ±50 ms
138 ±28 ms
9
0.0025%
160 ±50 ms
261 ±51 ms
CALL
-------
-------
-------
NOTE: Entries in this table are based on the assumption that both channels are set to the same sensitivity. To approximate response
add these times together.
Sensitivity 6 6 6 6
Delay Time 0 0 0 0
Extens ion Time
0 0 0
0
Max Presence Time
OFF
OFF
OFF
OFF
Presence / Pulse Mode
Presence
Presence
Presence
Presence
EOG
OFF
OFF
OFF
OFF
Option 1 - Loop Inductance Display
OFF
OFF
OFF
OFF
Option 2 - Loop Inductance -∆L/L Display
OFF
OFF
OFF
OFF
Option 3 - Call Extension Control
OFF
OFF
OFF
OFF
Option 4 - Noise Filt er Disable
OFF
OFF
OFF
OFF
Option 5 - Phase Green Loop Compensation
OFF
OFF
OFF
OFF
Option 9 - Third Car Passage
OFF
OFF
OFF
OFF
Option 10 - Dire c tional Logic
OFF
OFF
OFF
OFF
Option 11 - Audible Detect Signal
OFF
OFF
OFF
OFF
Option 12.0 - Detector Disconnect
OFF
OFF
OFF
OFF
Option 12.1 - Detector Disconnect Type
OFF
OFF
OFF
OFF
display LOOP FAIL o n the L CD. The type of loop failure will a lso be displayed as L lo (for -25 % chan ge or
shorted loop conditions) or L hi (for +25% change or open loop conditions). This will continue as long as 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 failure occurs in one (or more) loop(s) in
a group of two or more loops wired in 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 operation under all circumstances. At the time of a loop failure, the
channel’s LED will begin to flash at a rate of three flashes per second. The LED will continue this display pattern
until the channel is manually reset or power is removed. If the loop self-he als, the LOO P FAIL mess age on the
LCD will extinguish and the channel will re sume operation in a normal manner; exce pt the LED w ill continue the
three flashes per second display pattern, thus pro viding an alert that a prior Loop Fail condition has occurred. Each
loop failure for the channel is counted a nd accumulated into the Loop Fail Me mory. The total number of loop
failures written into the Loop Fail Memory (since the last power interruption or manual reset) is viewed by
stepping through the channel’s functions in Program Mode until the LO OP FAIL message is displayed.
3.4 TABLE: SENSITIVITY, -∆L/L, AND RESPO NSE TIME
Sensitivity -ΔL/L
time for a detector with the channels set to different sensitivities, look up the response time for each channel and divide it by two, then
Noise Filter Enabled
Noise Filter Disabled
3.5 TABLE: DEFAULT SETTINGS
Function Channel 1 Channel 2 Channel 3 Channel 4
Frequency 2 4 6 8
889-2103-01 Model U-1000 Operations Manual Page 9 of 26
Page 16
Pin
Function
Pin
Function
A
Power, Neutral, 120 VAC
A Power, Neutral, 120 VAC
B
Channel 4 Outp ut, Relay Common
B Channel 4 Outp ut, Emit ter (Source)
C
Power, Line, 120 VAC
C Power, Line, 120 VAC
D
Channel 1 Loop Input
D Channel 1 Loop Input
E
Channel 1 Loop Input
E Channel 1 Loop Input
F
Channel 2 Loop Input
F Channel 2 Loop Input
G
Channel 2 Loop Input
G Channel 2 Loop Input
H
Chassis Grou nd
H Chassis Grou nd
J
Channel 3 Loop Input
J Channel 3 Loop Input
K
Channel 3 Loop Input
K Channel 3 Loop Input
L
Channel 4 Loop Input
L Channel 4 Loop Input
M
Channel 4 Loop Input
M Channel 4 Loop Input
N
Channel 1 Outp ut, Relay Normally Open
N Channel 1 Output, Collector (Drain)
P
Channel 1 Outp ut, Relay Common
P Channel 1 Outp ut, Emit ter (Source)
R
Channel 2 Outp ut, Relay Common
R Channel 2 Outp ut, Emit ter (Source)
S
Channel 2 Outp ut, Relay Normally Open
S Channel 2 Output, Collector (Drain)
T
Channel 3 Outp ut, Relay Common
T Channel 3 Outp ut, Emit ter (Source)
U
Channel 3 Outp ut, Relay Normally Open
U Channel 3 Outp ut, Collector (D rain)
V
Channel 4 Outp ut, Relay Normally Open
V Channel 4 Output, Collector (Drain)
NOTE: Relay contact states are shown with power applied, loop(s) connected, and no vehicle(s) present.
Pin
Function
Pin
Function
A
Power, Neutral, 120 VAC
A Power, Neutral, 120 VAC
B
Channel 4 Output, Relay Common
B Channel 4 Output, Emitter (Source)
C
Power, Line, 120 VAC
C Power, Line, 120 VAC
D
Channel 1 Loop Input
D Channel 1 Loop Input
E
Channel 1 Loop Input
E Channel 1 Loop Input
F
Channel 2 Loop Input
F Channel 2 Loop Input
G
Channel 2 Loop Input
G Channel 2 Loop Input
H
Chassis Ground
H Chassis Ground
K
Channel 3 Loop Input
K Channel 3 Loop Input
L
Channel 4 Loop Input
L Channel 4 Loop Input
M
Channel 4 Loop Input
M Channel 4 Loop Input
N
Channel 1 Output, Relay Normally Open
N Channel 1 Output, Collector (Drain)
P
Channel 1 Output, Relay Common
P Channel 1 Output, Emitter (Source)
R
Channel 2 Output, Relay Normally Open
R Channel 2 Output, Collector (Drain)
S
Channel 2 Output, Relay Common
S Channel 2 Output, Emitter (Source)
T
Channel 3 Output, Relay Normally Open
T Channel 3 Output, Collector (Drain)
U
Channel 3 Output, Relay Common
U Channel 3 Output, Emitter (Source)
V
Channel 4 Output, Relay Normally Open
V Channel 4 Output, Collector (Drain)
NOTE: Relay contact states are shown with power applied, loop(s) connected, and no vehicle(s) present.
Pin
Wire Color
Function
1
Brown
Channel 1 Phase Green Input [Delay Override (120 VAC) Line]
2
Red
Channel 2 Phase Green Input [Delay Override (120 VAC) Line]
3
Orange
Channel 3 Phase Green Input [Delay Override (120 VAC) Line]
4
Yellow
Channel 4 Phase Green Input [Delay Override (120 VAC) Line]
connector is engaged.
3.6 TABLE: PIN ASSIGNMENTS
1200 SERIES
R
ELAY OUTPUTS SOLID STATE OUTPUTS
1100 SERIES
R
ELAY OUTPUTS SOLID STATE OUTPUTS
J Channel 3 Loop Input J Channel 3 Loop Input
4-PIN PHASE GREEN CONNECTOR (Mat ing harness P/N 4 15-2104-10 is included with the detector.)
NOTE: To eliminate any possibility of electric shock, this connector should only be engaged or removed when the primary MS
889-2103-01 Model U-1000 Operations Manual Page 10 of 26
The detector has no DIP switches or jumpers to configure. Connect an appropriately wired harness to the detector
and apply power. If the detector is not new from the factory, it may be advantageous to reset the detector back to
the factory defaults to avoid having t o check every setting for each channel. To reset the detector to factory
defaul t, pres s and ho ld all fo ur pus hbutto n switc hes simu ltaneo usly fo r five s econds . When a ll four b uttons are
depressed, the display will start count ing d own fro m five (5). Whe n the countdow n reaches zero (0), releasing the
pushbuttons will reload the factor y de fau lts and reset all channels.
All operating parameters can be adjusted from the front panel. The detector continues to operate normally while it
is in t he Program Mode . The value cur r ently displayed is alw ays the actua l value being use d. Exa mple: If you are
changing the delay time, the time displayed at the instant that a vehicle entered the detection zone for that channel
would be the value used for the delay timer.
Pressing the FUNC but to n e nt ers t he P ro g ra m M ode . The FU NC b utt o n ha s a n a ut o rep ea t f unc t io n. Th is a ll ows
quick navigation to the desired parameter. T he FUNC button only moves forward through all of the parameters.
There is no way to move backwards through the parameters.
While viewing any parameter, pressing t he CHAN button will display the same para meter for the next channel.
The currently selected channel is indicated at the bottom of the LCD. Pressing and holding the CHAN button for
one second will exit the Program Mode and return to the Normal Mode.
Pressi ng and ho lding e ither the (UP) or (D OWN) b utton wi ll cause the val ue to cha nge rap idly unt il the
button is released.
5.1 PROGRAM MODE DISPLAY SCREENS
PARAMETER ...................Frequency.
S
ETTINGS ........................Eight (8) Selections - 1 to 8.
S
ETTING DISPLAYED ......Bargraph indicates settings from 1 (left) to 8 (rig ht).
7
SEGMENT DISPLAY ......Actual Frequency of the loop circuit. Typically 20.0 to 99.9
ETTINGS ........................Presence or Pulse.
S
ETTING DISPLAYED ......The word PRESENCE or PULSE will be displayed.
7
SEGMENT DISPLAY ......Blank.
D
EFAULT SETTING..........Presence for all channels.
E
XAMPLE ........................Pulse Mode is selected for channel 1.
N
OTES .............................If the channel is in the call state when this parameter is
kilohertz.
frequency is 34.9 kHz.
frequency display varying more than ±0.2 kilohertz may
indicate loop crosstalk or other interference.
in the call state when viewing this parameter, the bargraph will
show t he s tre ngt h of veh icle ca lls s o tha t t he c orre ct s ens it ivit y
can be verified from this screen.
changed, the change will not take effect until the detection zone
is empty or the channel is reset.
889-2103-01 Model U-1000 Operations Manual Page 12 of 26
ETTING DISPLAYED ......The word ON or OFF will be displayed.
7
SEGMENT DISPLAY ......The number of this option.
D
EFAULT SETTING..........OFF for all channels.
E
XAMPLE ........................Option 10 is turned OFF for channels 1 and 2.
N
OTES .............................This is a paired channel option. Channel 1 is paired with
correctly connected to the controller phase green circuitry.
channel changes it for all channels. C ha nging t he sett ing of this
option will reset all detector channels. It is recommended that this option be set to OFF for normal operation.
correctly connected to the controller phase green circuitry.
channel 2 and Channel 3 is paired with c hannel 4. Changing
the setting for one channel also changes the setting for the
paired channel. Turning ON Option 9 a utomatically turns OFF
Option 10.
channel 2 and Channel 3 is paired with channel 4. Changing
the setting for one channel also changes the setting for the
paired channel. Turning ON Option 10 automatically turns
OFF Option 9.
889-2103-01 Model U-1000 Operations Manual Page 14 of 26
SEGMENT DISPLAY ................Model letter and fir mware version on
D
EFAULT SETTING....................Not Applicable.
E
XAMPLE ..................................Model U firmware version 34,
other c ha nne ls . T ur nin g it O N for one cha n ne l tu rns it O FF fo r
all other channels. T his option w ill automatically t urn OFF 15
minutes after being activated or on loss of power.
time is used as a Disconnect t ime. Operation of this option
requires that the Phase Green Inputs be correctly connected to
the controlle r phase green circuitry.
time is used as a Disconnect time and no extension of the call is
made. When Option 12.1 is turned OFF, Extension time is
active. Extension time and Disconnect time function
concurrently.
Fail memo r y.
to power failure.
channel 1.
(UP) or (DOWN) butt on, or by resett ing the c hannel.
one screen and firmware revision on
the other screen.
revision .00.
889-2103-01 Model U-1000 Operations Manual Page 15 of 26
XAMPLE ........................Channel 1 Loop / Lead-In circ uit i nd uct a nc e is 98 mic ro he n rie s
N
OTES .............................If Option 2 (-∆L/L D ispla y) is O N, th is di splay is onl y vis ible
by the vehicle exceeds the detection threshold (first dot =
current sensitivity level, second dot = next lower sensitivity
level, etc.) .
the detection threshold by five (5) sensitivity levels, there are
30 seconds of Max Presence remaining, and channel 1 is
outputting a call.
by the vehicle exceeds the detection threshold (first dot =
current sensitivity level, second dot = next lower sensitivity
level, etc.) .
flashing).
the detection threshold by five (5) sensitivity levels, Max
Presence has timed out and is waiting for the End Of Green,
and channel 1 is outputting a call.
by the vehicle exceeds the detection threshold (first dot =
current sensitivity level, second dot = next lower sensitivity
level, etc.) .
channel.
OFF).
the detection threshold by seven (7) sensitivity levels and
channel 1 is not outputting a ca ll. Either Option 9 (Third Car
Passage), Option 10 (Directional Logic), or Option 12 (Detector
Disconnect) has been selected.
output a call but is not, due to the operational functions of
Options 9 (Third Car Passage), Option 10 (Directional Logic),
or Option 12 (Detector Disconnect).
the inductance change caused by the vehicle exceeds the
detection threshold (firs t dot = current se nsitivity level, seco nd
dot = next lower sensitivity level, etc.) if a vehicle is detected.
exceeds 999, the display will alte rnate be tween the thousand s
place (1 or 2) and the lower three digits of the inductance value.
delay, extension, and /or pend ing as expected .
and channel 1 is not detecting a vehicle.
when the channel is not detect i ng a vehicle.
889-2103-01 Model U-1000 Operations Manual Page 17 of 26
% of Inductanc e 0.01 0.02 0.04 0.08 0.16 0.32 0.64 1.28 2.56 5.12
The Bargraph is a window that adjusts to the sensitivity setting.
5.3 LOOP FAIL INDICATIONS
If the tota l in ducta nce of a c hanne l’s l oop input netwo rk goes o ut of t he
range specified for the detector, or rapidly c hanges by more than ±25%,
the channel will enter the Fail-Safe mode and LOOP FAIL will be
displayed on the LCD. The type of loop failure will a ls o b e d is pla ye d a s
L lo (for -25% change or shorted loop cond itions) or L hi (for +25%
change or open loop conditions). This will cont inue as long as the loop
fault exists. Fail-Safe mode generates a continuous call in Presence
Mode and in Pulse Mode. At the time of a loop failure, the channel’s
LED will begin to flash at a rate of three flashes per second. The LED
will continue this disp lay pattern until the channel is manually reset or
power is removed.
If the loop self-heals, the LOOP FAIL message on the LCD will
exting uish and t he channel w ill resume operatio n in a norma l manner;
or open loop
condition.
or shorted loop
condition.
except, the LED will continue the three flashes per second display
pattern, thus, providing an alert that a prior Loop Fail condition has
occurred. Each loop failure is counted and accumulated into the Loop
Fail Memory. The total number of loop failures for the channel is written
into the Loop Fail Memory (since the last power interruption or manua l reset) and can be seen by stepp ing thro ugh
the channel’s f unctions in Program Mod e to the LOOP FAIL display.
This is a useful tool to identify intermittent loop prob lems. If the count is extremely high for the pe riod of time
observed, the problem is very likely a loose connection (check for loose connections at the terminal strip and bad
splices in the field). The Loop Fail Count is reset when power is removed from the detector. This prevents the
Loop Failure Count from moving to another loop, if the detector is moved to a new location.
To view the Loop Fail Count, repeatedly press t he FUNC bu tton unt il the LOOP FAIL display is shown. The Loop
Fail Co un t d is p lay is aft er the OP TI ON d is pla ys . P re ss in g th e (UP) or (DOWN) button while the Loop Fail
Count is displayed will reset the count to zero.
NOTE: The Loop Fail Count is not reset when the setting of Option 4 (Noise Filter Disable) is changed or when
the channel’s sensitivity or frequency is ch anged. The prior Loop Fail indic ation will continue u ntil the Lo op Fail
Count is reset to zero.
5.4 SETTING SENSITIVITY USING THE BARGRAPH
The bargraph is a graphical representation of the relative change of inductance as seen by the channel. It
automatically takes into account the channel’s sensitivity setting, loop geometry, configuration, lead-in length, etc.
The first bar segme nt rep resent s the minimu m induct ance c hange ( set b y the se nsiti vity le vel) ne cessa ry for t he
channe l to o utput a cal l. Eac h addi tiona l se gment t o the r ight repre sents the induct ance c hange in exc ess o f the
next se nsitivit y thresho l d . Us ually, the la r ger the vehicle, the greater the -∆L/L; thus, more and more segments are
displayed. The bargraph can be used as a precise indicator to select the proper sensitivity level.
The bar gr ap h be lo w s how s t he de fle ct io n ( 3 s egme nt s ) o f a ve h ic le w it h Se ns it iv it y se t to Le ve l 4. T he ve hic le i n
the loop zone is causing a change of inductance greater than 0.32% -ΔL/Lor Sensitivity Leve l 2.
889-2103-01 Model U-1000 Operations Manual Page 19 of 26
Page 26
Step 1: Observe a
of segments displayed
Step 2: Go to the
Program mode. Note
Step 3: Subtract the
actual number of
segments displayed
Increase the
Step 4: Verify that a
mobile causes the
bargraph to move
Step 5: A small
motorcycle should be
SENSITIVITY 10 9 8 7 6 5 4 3 2 1
% of Inductanc e 0.01 0.02 0.04 0.08 0.16 0.32 0.64 1.28 2.56 5.12
The Bargraph is a window that adjusts to the sensitivity setting.
PRESENCE
1
PRESENCE
1
PRESENCE
1
1
SENSITIVITY
1
The bargraph below has the same vehicle in the loop zone causing the same inductance change as above. Since the
sensitivity setting was increased to Level 7, six segments are now dis played. If the bargraph displays 5 or 6
segments for a vehicle in the loop and motorcycles are not a concern, the sensitivity has been set to the proper
range.
5.5 SETTING SENSITIVITY FOR MOTORCYCLE DETECTION USING THE
BARGRAPH
The bargraph can also be used to select the proper sensitivity level for small motorcycle detection. The relative
change of inductance caused by a motorcycle and a single automobile are proportional on any loop configuration.
Selecting the sensitivity level that causes the bargraph to display the seventh segment for a single standard
automobile automatically sets the sensitivity to detect small motorcyc les. Follow the steps below:
single standard automobile in the loop
zone. Note the number
on the bargraph. (4)
Note: This method applies to conventional loop configurations only. Other loop configurations, such as
Quadrupole
TM
the sensitivity level.
(3)
from the desired
number of 7. (7 - 4 =
3)
sensitivity thr ee levels.
, will require a different method to cor rectly set sensitiv ity for motorcycle detec tion. Increasing the
sensitivity to detect motorcycles in some loop configurations will make the loop sensitive to adjacent lane
detection. If adjacent lane traffic is detecte d, the phas e will max time when no vehicles are present in the loop (see
Option 5 - Phase Green Loop Compensation for a possible solution).
5.6 FULL RESTORE TO FACTORY DEFAULT SETTINGS
Pressing all four front pane l switches s imultaneo usly and c ontinuo usly for five (5 ) seconds resets t he detecto r and
restores all the factory default settings. The countdown of the five second period is displayed on the LCD.
Releasing any of the switches before the countdown ends aborts the Full Restore operation. (See Section 3.5 for
default settings.)
5.7 DISPLAY TEST
Pressing any two or three of the front panel switches simultaneously will turn on all possible symbols and
messages on the LCD.
889-2103-01 Model U-1000 Operations Manual Page 20 of 26
single standard auto-
seven segments.
detected causing a one
segment deflection.
Page 27
Channel 1
Loop
Loop
Loop
Non-volatile
Channel 2
Loop
Isolation
Loop
Oscillator
Channel 3
Loop
Isolation
Loop
Oscillator
Channel 4
Loop
Loop
Squaring Circuit
DETECT
Ch. 1 Phase Green Input
LCD
Ch. 2 Phase Green Input
Ch. 3 Phase Green Input
Ch. 4 Phase Green Input
120 VAC
Vs
+5 VDC
GND
Front Panel
32 MHz
Oscillator
Detect
Loop
Capacitors
Loop
Capacitors
Loop
Section 6 Block Diagram
Loop Inputs
Loop Inputs
Loop Inputs
Loop Inputs
Input
Power
Isolation
Isolation
Power
Supply
Oscillator
Oscillator
Capacitors
Capacitors
Micro Controller
Memory
LEDs
Push Button
Switches
Outputs
889-2103-01 Model U-1000 Operations Manual Page 21 of 26
Page 28
Section 7 Theory of Operation
The Reno A & E Model U-1000 d e te c t or d i gi tally mea s ur es changes in the reso nant fre quency of fo u r i n de p e nd e nt
loop circuits to determine if a vehicle has entered the detection zone. The Model U -1000 Series detector applies an
excitat ion vo ltage t o each lo op circ uit re sultin g in the loops os cillat ing at t heir re sonant freque ncy. The curre nt
flow in the loop wire creates ma gnetic fields a round the loop w ire. When a vehicle pa sses 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 of change can be determined. If the frequency change exceeds a selectable
thres hold (se t b y the s ens it ivit y se tt ings) , t he c han nel w il l act iva te a n out pu t sig na l. I f the r ate of c ha nge is s low,
typical of environme ntal drift, t he cha nne l wi ll co nt in uous l y t ra ck and c o mpe nsa te fo r t he c ha nge . The Mo d el U 1000 detector also monitors the loop frequency for out of range conditions such as an open or shorted loop circuit.
The Model U-1000 detector is a sca nning detector. The sca nning metho d se quent ial ly tu rns e ach c hanne l’s loop
oscillators on and off. Each channel’s os cillator circuit supplies the e xcitation voltage that is coup led to the loop
circuit by a loop isolation transformer. The channel’s oscillator circuit supplies the excitation voltage that is
coupled to the loop circuit by a loop isolation transformer. The tra nsformer pro vides high co mmon mode iso lation
between the loop and detector electronics , which allows the channel to o perate on poor quality loops including a
single short to gro und. The transformer also limits the a mount of static energy (lightning) that ca n transfer to the
detector electronics. A spark gap transient suppression device is connected across the loop inputs connected to the
isolat ion trans for mer . This device dissipates static charges before they reach the transformer. A network of four
capacitors is connected to the detector side of the isolation transformer. Three of the capacitors can be switched in
or out of the oscillator circuit to shift the frequency of the loop oscillator circuit thus providing frequency
separation between adjacent loops. The three switchable capacitors are electronically switched using FETs and are
select ed when p rogram ming parameter values with the front panel pushbutto n switches.
The outputs from the four loop oscillators are tied together and fed into a co mmon squaring circuit. This is
possible since the detector is a scanning detector that allows only a single loop oscillator to be operat ing at any
given t ime. The sine wave fro m the loop oscillator circuit is squared to provide a precise zero cross ing signal for
the input to the microcontroller. This s ignal is called the loop sa mple. The loop sample is an integral number o f
complete oscillations from the loop oscillator circuit. The number of loop oscillations c ounted is a function of the
selected sensitivity setting for the channel. The required nu mber of loop oscillations needed for a loop sample
increases as the sensitivity setting is increased. The microcontroller uses the period of the loop sample for
accumulating high-speed (32 MHz) cr ystal clock pulses generated by the microc ontroller’s internal high-speed
crystal oscillator. The number of crystal clock pulses accumulated during consecutive loop samples is compared to
the internal reference number of crystal clock pulses stored in the microcontroller’s memory.
When a vehicle enters the loop zone the loop inductance decreases. This decrease in loop inductance causes an
increa se in t he loop osc illat or fre que ncy. In turn, an increase in loop oscillator frequency results in a decrease of
the time period for the loop sample. Hence, when a vehicle enters the loop zone the number of crystal clock pulses
accumulated during a loop sample period decreases. By comparing t he new count with the reference count, a
percentage change can be calculated that indirectly relates to the inductance change. If the magnitude of the
change exceeds a selectable threshold (sensitivity setting), the channel activates an output device. The rate of
change is also monitored. Slow rates of change caused by environmental fluctuations are tracked and
automatically compensated for.
The microcontroller uses the high-speed crystal clock count to calculate the loop inductance, frequency and
percentage of change. If selected, the values are displayed on the seven segment LCD. The microcontroller also
processes the pushbutton switch selections for the LCD and stores the operating parameters in non-volatile
memory. Stored parameters are only changed wit h the front pa nel switches a nd are unaffected by los s o f power or
channel reset. The microcontroller continuo usly processes the loop samples and the detect or operation is not
affected during the operation of the switches or the LCD. (Note: When e ither channel’s sensitivity o r frequ ency is
change d, that channel is reset .)
In add ition, the microc ont rolle r co nditi ons the out puts base d on P hase G ree n Inpu ts and the pr ogra mme d sett ings
of the various t imers (De lay, Ext ension, and Max Presence ) and opt ions (EOG, Option 3, Option 4, Opt ion 5,
Option 9, Option 10, and Option 12).
889-2103-01 Model U-1000 Operations Manual Page 22 of 26
Page 29
Symptom
Where To Start
No LCD display and no LEDs lit.
See Troubleshooting Power Problems.
LCD displays garbage and detector does not respond to
button presses.
Detector does not respond to button presses.
See Troubleshooting Initialization Problems.
LCD continually displays
L lo and Loop Fail or L hi and L oop Fail.
The channel detect LED is flashing three times per
second and channel appears to be working correctly.
Detector intermittently stays in the Call state.
See Troubleshooting Intermittent channel Lock Ups.
A channe l will not t ime delay.
See Troubleshooting Delay Problems.
A channel does not always time delay.
See Troubleshooting Delay Problems.
One of the paired channel options (Option 9 or 10) or detector disconnect
(Option 12.0) has been tu rned on.
A channel does no t always t ime extension.
Option 3 is on.
EOG is t urned on and the Phase Green Inp ut for the channel is not
transitioning from green to not green.
The sensitivity for the c hannel has been set to Call for cing the c hannel to
output a constant call.
Section 8 Maintenance and Troubleshooting
The Reno A & E Model U-1000 Detector requires no mainte nance. If you are having problems w ith your Model
U-1000 detector, use the troubleshooting chart below to help determine the cause of the problem.
See Troubleshooting Initialization Problems.
See Troubleshooting Loop Fail Problems.
See Troubleshooting Intermittent Loop Fail Problems.
LCD disp lays Pnd and a ch annel doe s not output a call.
Max Presence never resets the channel.
LCD alwa ys displays a flashing Call.
8.1 TROUBLESHOOTING POWER PROBLEMS
Does the LCD display anything when the detector is powered up?
NO, Do any of the detectors in the cabinet display anything when powered up?
NO, Check the AC Po wer Supp ly voltage. Is it greater than 89 VAC and less than 135 VAC ?
NO, Determine why AC power is out of tolerance and have it corrected.
YES, Wiring from the AC Power Supply to detector is incorrect or defective.
YES, Swap the detector with a working detector. Did the problem follow the swapped
detector?
NO, Confirm correct wiring of the harness and that the pins in the connector are not
damaged.
YES, The swapped unit is defective. Replace the unit.
YES, Probably not a power related problem.
8.2 TROUBLESHOOTING INITIALIZATION PROBLEMS
Does t he LCD dis play the Model and Firmware version when powered up?
NO, Replace the detector with a known good unit. Does the LCD display the Model and Firmware
version when p o wered up?
NO, The connector or wiring harness is defective. Confirm correct wiring of the harness and
that the connector is not defective or damaged. Check for unexpected voltages on any pin.
YES, Replaced unit was defective.
YES, After two seconds, are three dashes, Call, Off, or a Loop Fail message displayed on the LC D?
NO, Replace the detector with a k nown good unit. After two seconds, are three dashes, Call,
Off, or a Loop Fail message displayed on the LCD?
NO, The connector or wiring harness is defective. Confirm correct wiring of the
harness and that the connector is not defec tive or damaged. Check for unexpected
volta ges on any pin.
YES, Replaced unit was defective.
YES, The unit is initializing correctly.
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8.3 TROUBLESHOOTING LOOP FAIL PROBLEMS
Check e ach c hanne l’s s tat us by mo ment ar ily pre ssi ng the C HAN butt on to s tep t hro ugh the cha nnels . Do a ny of
the channels d isplay L hi and Loop Fail?
NO, Do any of the channels display L lo and Loop Fail?
NO, All channels have tuned up to the existing loop / lead-in circuits and are within acceptable
limits.
YES, There is probably a short in the loop / lead-in circuit. Disconnect the loop from the
terminal block in the cabinet. Does the status of that channel now show L hiLoop Fail?
NO, The problem is in the cabinet. Replace the detector with a known good unit.
Does t he status of that channel now show L hiLoop Fail?
NO, The detector is not the problem. Measure the resistance from each
loop terminal to the pin in t he connec tor. It s hould read less than 0 .5
Ohms for both terminals. Check all wiring from terminal block to the
connector in the harness. Also, check that the connector itself is not
defective.
YES, The replaced unit was defective.
YES, The problem is in the field, either a short in t he loop / lead-in circuit or
insufficient inductance in the loop / lead-in circuit. Leave the loop disconnected in
the cabinet. Connect a MegOhm meter set to 500 volts to one of the loop wires and
earth grou nd. Is the r esistance 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 as close as possible to where
the loop enters the pavement. Measure the resistance between one of the
loop wires and earth ground. Is the resistance greater than 50 megOhms?
NO, The loop is damaged. Replace the loop.
YES, The lead-in cable is defective. Replace lead-in cable.
YES, The problem is insufficie nt inductance in the loop / lead-in circuit.
This ind icates too fe w turns in the loo p itself or some of the turns are
shorted to each other. In either case, the loop must be replaced to correct
the problem.
YES, If a cha nne l is not be ing us ed, you wil l se e this dis pla y if the cha nne l has not be en tu rne d of f. Is
there a loop connected to this channel?
NO, Chan ge the channel’s sensitivity setting to OFF and the Loop Fail message will no longer
be displayed for the channel.
YES, There is an open or high resistance in the loop / lead-in circuit. Short across the loop
inputs on the t erminal b lock in the cabinet. Does the status of that channel now s how L lo Loop Fail?
NO, The problem is in the cabinet. Replace the detector with a known good unit.
Does t he s t atus of t ha t channe l no w show L lo Loo p Fail with the short still ap plied
at the loop terminals?
NO, The detector is not the problem. Measure the resistance from each
loop terminal to the pin in the connector. It s hould read less than 0.5
Ohms for both terminals. Check all wiring from terminal block to the
connector in the harness. Also, check that the connector itself is not
defective.
YES, The replaced unit was defective.
YES, The open or high resistance is in the field. With the loop still disconnected,
measure the resistance of the loop / lead-in cir c uit ( fro m o ne 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 O hms?
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 problem is probably excessive inductance. Are there several
loops connected in series for the loop / lead-in circuit?
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NO, This is typic ally cause d by having too many t urns in a
large loop. Replace the loop with one that has an inductance of
less than 2000 microhenries.
YES, If possible, connecting each loop to its own c hannel is
preferred. Or try a parallel wiring arrange ment for the loops if
separate detection channels are not possible.
Have you been able to see the channel display while the loop failure was occurring?
NO, Loop Fail problems tend to be bad splices in the loop / lead-in circuit, shorts in the loop / lead-in
circuit, shorts to earth ground in the loop / le ad-in circuit, or loose co nnections or bad s older joints 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 t han 50 megOhms. I nspect 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 harness itself.
Disconnect and reconnect any connector used in the loop circuit and check for loose pins and sockets in
these c onnect ors. If your ca binet ha s ligh tning or surge s uppres sion de vices on the lo op inp uts in the
cabinet, remove or replace them. Check for places in the field where the loop wire or lead-in cable ma y
be pinched or chaffed. Look for wires pinched under j unction box covers and w here 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.
YES, Did t he display show L h i?
NO, The display must have bee n L lo then. This indica tes an intermittent shorted loop or -
25% inductance change. Using a Me gO hm 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. 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 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 cabinet, remove or replace them.
YES, This indicates an intermittent open loop or +25% inductance change. 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. Tighten all screw terminals in the s ignal cabinet that t he loop circuit
uses. Check solder joints in the loop circuit, especially on the harness itself. Disconnect and
reconnect any connector used in the loop c ircuit and check for loose pins and socke ts in these
connectors.
Have you been able to see the channel display while the loop was locked up?
NO, See Troubleshooting Intermittent Loop Fail Problems and follow the path for unable to see the
channel display while the loop failure was occurring.
YES, Were more than t wo segments lit in the ba rgraph on the LCD?
NO, Problems of this type tend to be difficult to isolate due to the many pos sible causes and
the short duration of the symptom (usually less than 30 minutes). I f the problem occurs more
frequently in the morning or when raining, s uspect a short to ea rth ground in t he loop / lead-in
circuit. This can usually be verified 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 the street near the loop may also be a source of
problems. Ensure that lids near a loop are bolted down so that they cannot move. Check that
each set of loop wires is twisted together in each pull box and that lengths are not excessive.
And also see
loop failure that displays L lo on the LCD.
YES, See Troubleshooting Intermittent Loop Fail Problems and follow the path for a loop
failure that displays L lo o n the LCD.
Troubleshooting I ntermittent Loop Fail Pr oblems and follow the path for a
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8.6 TROUBLESHOOTING DELAY PROBLEMS
Does the channel ever time the Delay function?
NO, Is the P has e Gr ee n Inp ut, for t he c hanne l ha vin g a prob lem, connected to a po int that will be at 89
VAC to 135 VAC when the green associated with this channel of detection is on?
NO, Conne ct the Phase Green Input t o an app r opriate point.
YES, Disconnect the Phase Green Input from the phase green and leave it disconnected. Does
the Delay function now time?
NO, Replace the detector and ensure that there is delay time programmed. Does the
new channel time the Delay function correctly ?
NO, The problem is in the wiring from the phase green to the wiring
harness or the connector itself. The Phase Green Input lead is shorted to
ground somewhere.
YES, The channel has a bad Phase Green Input circuit.
YES, The point you are using to get phase green is always at a high pote ntial
(great er than 89 VAC) or the phase actually is green all of the time.
YES, Reme mber that t he d e lay funct i o n is o n ly availa b le w hen the Pha s e Gr e e n I nput is be lo w 89 V AC .
If you want the delay function available all of the time, disconnect the Phase Green Input. If you are
aware of this and the delay function still does not function at the correct times then the Phase Green
Input, is connected to the wrong phase green. Connect the Phase Green Input to an appropriate point.
8.7 THINGS TO KNOW ABOUT LOOPS
Always use a wire with cross-linke d Polyet hylene insu lation (insulation type XLPE) for loo p wire.
Typical sensing height is ⅔ of the shortest leg of a loo p. Therefore, a 6΄ x 6΄ loop will have a detection heig ht 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 microhenries
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 indu c tance 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