Feig Electronic VEK FG2 Series User manual

Operating instructions
Diagnostic device
VEK FG2-1
FEIG ELECTRONIC GmbH Lange Straße 4 35781 Weilburg

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 5
General
Copyright 1998 by FEIG ELECTRONIC GmbH
Lange Straße 4
D - 35781 Weilburg
The indications made in these operating instructions may be altered without previous notice.
With the edition of these instructions, all previous editions become void.
Composition of the information given in this manual has been done to the best of our knowledge. FEIG
ELECTRONIC does not guarantee the correctness of the details given in these instructions and may not be
held liable for damages ensuing from incorrect installation.
Since, despite all our efforts, errors may not be completely avoided, we are always grateful for your useful
tips.
The installation instructions given in this manual are based on advantageous boundary conditions. FEIG
ELECTRONIC does not give any guarantee promise for perfect function of the appliance in a cross
surrounding.
Copy or reproduction of these instructions, even if only partial, as well as translation into other languages is
forbidden unless a written consent has been granted by FEIG ELECTRONIC. This also applies to the
complete or partial storage of these operating instructions on modern input- and output media for further
processing in data processing systems.
Please read the operating- and safety instructions thoroughly before putting the appliance into
operation !
Stand: 28.05.98 as
BES_FG2.DOC, L-6490

operating instructions VEK FG2-1
6 12/99 FEIG ELECTRONIC GmbH
Contents
1 Introduction .....................................................................................................................................................7
2 Operation ........................................................................................................................................................7
2.1 Initiation ....................................................................................................................................................7
2.1.1 Frequency..........................................................................................................................................8
2.1.2 Detuning.............................................................................................................................................8
2.1.3 Number of vehicles............................................................................................................................ 9
2.2 Error messages........................................................................................................................................9
2.3 Automatic cutoff........................................................................................................................................9
2.4 How to charge the accumulator..............................................................................................................10
3 Technical data...............................................................................................................................................10
4 Accessories...................................................................................................................................................11
4.1 contract accessories...............................................................................................................................11
4.2 optional accessories...............................................................................................................................11
5 Initiation of induction loop detectors..............................................................................................................11
5.1 Loop installation......................................................................................................................................11
5.1.1 mechanical handicaps .....................................................................................................................11
5.1.2 electrical handicaps .........................................................................................................................12
5.2 How to align the detector........................................................................................................................12
5.3 How to adjust the detector......................................................................................................................12
5.3.1 Sensitivity.........................................................................................................................................12
5.3.2 Stop period.......................................................................................................................................12
5.3.3 Frequency .......................................................................................................................................12
6 Safety- and danger instructions ....................................................................................................................13
7 Appendix .......................................................................................................................................................14
7.1 Survey of detectors.................................................................................................................................14
7.2 Number of turns for square loops...........................................................................................................14
7.3 Selection of sensitivity............................................................................................................................15
7.4 Order data ..............................................................................................................................................15
8 Malfunctions..................................................................................................................................................16
9 Index .............................................................................................................................................................21

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 7
1 Introduction
The diagnostic device VEK FG2 is a measuring device to be used for control and trouble shooting of
induction loop detectors. With its 16-digit LCD display, it is able to indicate the frequencies of the various
loops of a detector. Thus, couplings between neighbouring loops, which occur due to a too small distance
between the base frequencies may be avoided. Furthermore, it facilitates the indication of a detuning of the
resonant circuit, as it is caused by a vehicle crossing the loop. Consequently, the responsiveness of the
detector may be perfectly adjusted. Short circuits or interruption of the loops are indicated likewise.
2 Operation
FEIG
ELECTRONIC
Diagnoseeinheit
VEK FG2
Obere Stellung:
Grundfrequenz
Untere Stellung:
Verstimmung
Schiebeschalter
Buchse fü
r
Diagnosekabel Taster für
Kanalumschaltung
Gerät
aus
Frequenzaneige
CH1 o .000 kHz
Klinkenbuchse 3.5mm
für Stecknetzteil
2.1 Initiation
Please charge the 9V-block accumulator prior to putting the device into operation. (see:how to charge the
accumulator)
With the help of the VEK FG2, loop diagnosis may be carried out at two different detector types at a time.
a) Detectors with 10-pole diagnostic socket
The VEK M... detectors are constantly sending the data currently determined by the micro processor
through the diagnostic socket. The VEK FG2 then reads this data, edits it and shows it on the display.
b) Detectors with frequency measuring sockets
For these older detectors of type VEK V..., the diagnostic device is connected parallel to the resonant
circuit of the detector. The diagnostic device internally simulates the complete function of a detector
at the highest sensitivity level. It determines the frequency of the resonant circuit and has the same
rebalancing mechanisms as the detector.
As accessories, two diagnostic cables come together with the VEK FG2. Furthermore, one cable with 3
bunch plugs (cable V) as well as a cable with a 10-pole diagnostic plug (cable M). Both cables end in a
western modular plug. This plug is put into the appropriate socket located at the upper side of the housing.

operating instructions VEK FG2-1
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The diagnostic device is able to recognize which detector type has been connected by means of the cable
that has been connected. Please refer to the charts in „Survey of detectors“ in order to find out which cable is
used for which detector.
A flashing decimal point on the display means that the detector is working, i.e. a frequency is fed to the
diagnostic cable or the diagnostic device is receiving data through the 10-pole diagnostic plug.
2.1.1 Frequency
In the position base frequency (slide switch up) the LCD-display shows the frequency of the detector
resonant circuit. It accrues from the loop inductivity and a possible crossing of the loop field by a vehicle. If
the loop is not covered, this frequency is the same as the base frequency of the detector. The relative
frequency changes of the resonant circuit, as indicated in position detuning (see detuning) , refer to this base
frequency.
Example:
The first thing that is indicated after having switched on the device, is the frequency of the first detector
channel. Press the key button located on the upper side to switch to the next channel. The diagnostic device
VEK FG2 is able to process the data of up to 4 detector channels and display it one after the other.
2.1.2 Detuning
The detuning display indicates the extent of the frequency change which has been caused by crossing the
loop with a metallic vehicle. A vehicle causes a change of inductivity at the loop, which means a relative
change of frequency. Therefore, the detuning is indicated as a relative value (increments) and not in Hz. The
responsiveness of the detector may be perfectly adjusted by using the indicated detuning and the charts
listed under „Selection of sensitivity“.
In order to activate the detuning display, the lateral slide switch has to be put in Detuning position (slide
switch down).
Now, the display shows the data of the first detector channel. You may then switch to the next channel by
shortly pressing the channel selection button located on the upper side of the housing.
The display now shows the following data:
•Selected detector channel
•Current detuning as a relative value compared to base frequency
•minimum detuning since the diagnostic device has been switched on
•maximum detuning since the diagnostic device has been switched on
Example:
In order to be able to discern the change of the detuning values from increasing to dropping and vice versa,
the display stays on current detuning for approx. 0,5s when reaching the inflection point. Due to this, all
saddle- and inflection points of the detuning curve may be determined by gradually crossing the loop.
CH1 94.078 kHz
Frequencyz
Det. channel
1 675. 98 1300
Current
detunin
g
Maximum
detuning
Det. channel Minimum
detuning

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 9
2.1.3 Number of vehicles
For each channel, one counter may be polled. This counter determines the number of vehicles resp.
detunings. It counts all vehicles, which cause a detuning of at least 10 increments at the loop. The count of
the counter is deleted by switching off the device.
In the detuning mode, (slide switch down) the counted number of vehicles of the selected detector channel is
displayed by pressing the channel selector key for a longer time. Press the key briefly in order to re-activate
the detuning display as described under „Detuning“.
Example:
2.2 Error messages
The display of the diagnostic device may show the following errors resp. messages:
* Battery warning
o Breach of loop
% Loop short
< Frequency exceeding
> Frequency underflow
The error memory of a channel is deleted by switching to the next channel.
Example:
2.3 Automatic cutoff
In order to avoid unnecessary stressing of the storage battery and thus a total discharge, the device is
automatically switched off 2 minutes after the diagnostic cable has been removed from the detector. Cutoff of
the device is delayed by 2 minutes by pressing the channel selection switch. Thus, the logging of the detector
data may be carried out at a later point of time (e.g. in the service vehicle). After automatic cutoff, the device
may be restarted by operating the slide switch.
1 _2. 27 342
Number of
vehicles Maximum
detunin
g
Det. channel Minimum
detuning
CH1 * 94.078 kHz
CH1 % 16.566 kHz
Loop short
Battery empty

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2.4 How to charge the accumulator
The 9V-accumulator may be charged with the accompanying plug power pack. The accumulator may remain
in the battery compartment for charging. The plug power pack, which has been adjusted at 12V=, feeds the
charging connection with a 3,5mm-jack bush. It is not necessary to switch on the diagnostic device in order to
start the charging process. The accumulator needs approx. 14 hours until it is fully charged.
Warning: In case of power pack operation, a conventional 9V-block battery has to be removed from the
battery compartment. Otherwise there is danger of destruction !
Polarity at the 3,5mm-jack bush:
-+
The 9V-accumulator may also be charged with an external battery charger.
3 Technical Data
Power supply 9V accumulator or
12V DC plug power pack
Service life Akku Varta 5022 approx. 3 hours
Charging Conventional battery charger by removing the accumulator
or directly with power pack 12V DC via charging bush,
total charging 14 h
Temperature range 0 to 50°C
Storage temperature -20 to 50°C
Measuring range 10 - 150 kHz
Measuring accuracy +/- 1 Digit
Display LCD 1 x 16 Character
Housing Plastic housing with battery compartment
30 x 80 x 150 (H x B x L)
Weight 190 g (without battery)
Protection class IP 40

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 11
4 Accessories
4.1 Contract accessories
•Cable V: modular plug with flat cable at 3 bunch plugs
Colour code:
red CH1
blue CH2
black GND
•Cable M: modular plug with flat cable at 10-pole diagnostic plug
•Power pack
•9V accumulator (has to be charged prior to initiation !)
•Service box
•Operating instructions for diagnostic device
4.2 Optional accessories
•Cable M9: 9-pole Sub-D plug,
same functions as cable M, but other plug form for special detectors
Item No.: VEK FG2 S3/M8 Diagnostic cable Order No.: 548
•Cable M4: 4-pole plug,
same functions as cable M, but other plug form for special detectors
Item No.: VEK FG2 SVEK diagnostic cable Order No.: 782
•LCR Meter: fits in service box
Item No.: VEK FG LCR Diagnostic measuring instruments Order No.: 546
5 Initiation of induction loop detectors
5.1 Loop installation
5.1.1 Mechanical handicaps
In order to determine the minimum distance between the loops, the following rule applies:
Distance between
two loops =At least half of the length of the parallel edge
The loops of a multiplex detector (e.g. VEK M...) do not affect each other. There is no need for a minimum
distance, which means that the loops may be interlaced without impairing the functioning of the device.
The size of the loop should be suitable so that the vehicle can be recognized. An optimum loop is covered
completely by the object crossing it.
The mechanical fixing of the loop has to be tight, in order to avoid malfunctions of the detector and
deformations of the loop geometry while vehicles are crossing. For this reason, only finished loops should be
used under paving stones.
The loop lead has to be thoroughly twisted (at least 25 twists/m) and installed in appropriate distance to other
live leads. Otherwise, disturbances may occur in the loop lead.
The diameter of the loop wire should be between 0,5mm2and 1,5mm2.

operating instructions VEK FG2-1
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5.1.2 Electrical handicaps
In order to be able to guarantee smooth operation of a loop, the required electrical values of the loop have to
be observed.
Resistance less than 20
Ω
Inductivity 50
µ
H to 1000
µ
H
Isolation resistance More than 2M
Ω
Loop resistance and inductivity may be checked with the help of an LCR-meter. The loop’s insulating
resistance against ground has to be measured with a ground tester at a measuring voltage of at least 500V.1
5.2 How to align the detector
The detector has to be aligned with the loops not occupied and is activated by pressing the reset key. For
most detectors, the alignment process is indicated by the flashing of a luminous diode. The alignment
process is completed after approx. 3s .
Automatic alignment is activated when switching on power supply (only for detectors without buffering). After
changing the frequency level, please carry out re-alignment!
5.3 How to adjust the detector
5.3.1 Sensitivity
The detector’s response level is determined by the selected sensitivity level.
For perfect adjustment, the loop is crossed by a passenger car. The minimum detuning that has been caused
by the car is then measured with diagnostic device VEK FG2. Possible sensitivity levels depending upon the
detuning are listed in the chart under „Selection of sensitivity“
Note:
In case of vehicles with a great distance between bottom of the car body and loop (lorries, trucksters, all-
terrain vehicles etc.), only the axles are detected if sensitivity is too low. In between the axles, the detector
falls back into the non-occupied condition. In this case, please choose a higher sensitivity level.
5.3.2 Stop period
For safety loops in for example barrier systems, the stop period should be set on infinite. With this
adjustment, vehicles on the loop are recognized and signalized for an infinite period of time. The busy signal
of the loop is not de-activated until the vehicle has left the loop.
If a limited stop period has been adjusted, (e.g. 5 minutes) it is easier for the detector to level out
interferences.
5.3.3 Frequency level
Loop frequencies have to be adjusted in a way that there is no coupling between other loops resp. detectors.
Please keep a frequency separation of at least 5 kHz for non-multiplex (VEK V...) and 10 kHz for multiplex
detectors (VEK M...).
Influences of high-frequency sources of interference may be avoided by selecting another frequency level.
With the help of the diagnostic device, the working frequency of the single channels may be measured and
checked in the base frequency position.
1Order data for LCR-Meter and ground tester are to be found in the appendix

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 13
6 Safety- and danger instructions
•The appliance shall only be used for the purpose intended by the manufacturer.
•The operating instructions are to be handed out to every user and should be stored in an easily accessible
place.
•Improper changes as well as the use of spare parts and accessories, that are not sold or recommended
by the manufacturer of the appliance, may cause fire, electric shock and injuries. Such measures
therefore lead to nonliability and the manufacturer does not grant any guarantee.
•For this appliance, the manufacturer’s guarantee clauses apply in the version valid at the time of
purchase. The manufacturer may not be held liable for improper or wrong manual or automatic
adjustment of parameters resp. improper use of the appliance.
•Repair work should only be carried out by the manufacturer.
•Connection, initiation, maintenance, measurement and adjustment of the traffic detector should only be
carried out by electricians with special knowledge regarding accident prevention.
•When handling appliances which come into contact with electricity, the current VDE-rules have to be
observed - especially VDE 0100, VDE 0550/0551, VDE 0700, VDE 0711, VDE 0860, VDE 0105 as well as
the fire- and accident prevention rule VBG4.
•The extinguishing of an operation indicator is no proof that the appliance is disconnected and idle.
•All works carried out on the appliance as well as its installation have to be done in compliance with the
national electric regulations and local prescriptions.
•The user is responsible for the correct mounting and connection of the appliance according to the
technical regulations of the country of installation as well as other regional prescriptions. Special attention
should be paid to cable dimensions, fuse protection, earthing, cutoff, disconnection, ground testing and
excess current protection.

operating instructions VEK FG2-1
14 12/99 FEIG ELECTRONIC GmbH
7 Appendix
7.1 Survey of detectors
a) Non-multiplex detectors
Item No. Diagnostic cable
VEK V1A V
VEK V1B3 V
VEK V1C-DC V
VEK V1CK V
VEK V1E V
VEK V2A V
VEK V2B3 V
VEK V2C-DC V
VEK VP1B3 V
VEK VP2B3- V
VEK VRA V
VEK VRB V
VEK VPRD V
b) Multiplex detectors
Item No. Diagnostic cable
VEK M1A M
VEK M2A M
VEK M1B M
VEK M2B M
VEK M2C M
VEK M4C M
VEK M4CS M
VEK MP2RC M
VEK M1E M
VEK M2E M
VEK MRE M
VEK M8ER M9
VEK S3 M9
TST SVEK1 M4
TST SVEK2 M4
Cables M9 and M4 have the same functions as cable M and may be purchased as accessory parts.
(see „Optional accessories“)
7.2 Number of turns of square loops
Loop circumference Number of turns
2 - 3m 6
3 - 4m 5
4 - 6m 4
6 - 12m 3
> 12m 2

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 15
7.3 Selection of sensitivity
The following detuning values refer to a standard passenger car.
a) Detectors with 8 sensitivity levels
(e.g. VEK V2A, VEK M2B)
Indicated
detuning Recommended sensitivity level
> 2000 1
1600 – 2000 2
1200 – 1600 3
800 – 1200 4
400 – 800 5
200 – 400 6
100 – 200 7
< 100 8
b) Detectors with 4 sensitivity levels
(z.B. VEK M2E, VEK M1E)
Indicated
detuning Recommended sensitivity level
>1600 low
800 – 1600 med. low
200 – 800 med. high
< 200 high
7.4 Order data
a) VEK FG2 A Diagnostic set Order No. 544
- Diagnostic device VEK FG2,
- Plug power pack
- 9V-accumulator
- Cable-M
- Cable-V
– Service box
b) VEK FG2 B Diagnostic set Order No. 543
just like a), but with an additional
- LCR-meter with test strings
c) VEK FG LCR Diagnostic measuring instrument order No. 546
- LCR- meter, suitable for service box
d) VEK FG ISO ground tester order no. 586
- ground tester with test strings and
ever-ready case
e) VEK FG2 S3/M8 diagnostic cable order no. 548
- Cable M9: 9-pole diagnostic cable for VEK S3 and VEK M8ER
f) VEK FG2 SVEK Diagnostic cable order no.782
- Cable M4: 4-pole diagnostic cable for TST SVEKx

operating instructions VEK FG2-1
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8 Malfunctions
Detector does not align correctly or not at all
Possible reasons Measures
Break of loop or short
circuit Verification: measure resistance and inductivity of the loop with an LCR-meter.
- total resistance has to be between 0 and 20 Ω.
- total inductivity has to be between 50 and 1000 µH.
Remedy: eliminate the source of errors, install new loop resp. loop feeder.
Insulation defect Verification: check insulating resistance of the loop and feeder between feeder end and earth potential with
the
help of an insulation tester, such as the Isolavi. The insulating resistance has to be higher than
2 MΩ.
Remedy: eliminate the source of errors, install new loop resp. loop feeder
Inductivity is too high Verification: check inductivity with an LCR-meter.
Total inductivity of loop and loop feeder must not exceed 800µH .
Remedy: - install interstage transformer VEK ANPASS into the loop feeder.
- install a new loop with less turns. (see „loop installation“)
Inductivity is too low Verification: check inductivity with an LCR-meter.
Total inductivity of loop and loop feeder has to exceed 30µH.
Remedy: -install interstage transformer VEK ANPASS into the loop feeder.
- install a new loop with more turns. (see „loop installation)
Resistance is too high Verification: check resistance with an LCR-meter or multimeter.
Total resistance of loop and loop feeder has to be less than 20Ω.
Remedy: reduce loop feeder resistance by
- connect two leads in parallel
- use a cable with a greater diameter
Loop feeder is too long Verification: check feeder length between detector and induction loop according to detector data sheet.
Remedy: -install interstage transformer VEK ANPASS between detector and loop feeder.
- place the detector resp. loop elsewhere.
Couplings caused by
deficient frequency
separation
Verification: check frequencies of all loops with diagnostic device VEK FG2. Frequency separation of
neighbouring loops has to be at least 5 kHz (VEK V..-types) resp. 10 kHz (VEK M..-types).
Note: For multiplex detectors (VEK M...), frequency separation is not necessary for loops of one
detector.
Remedy: re-adjust loop frequencies and check with diagnostic device VEK FG2.
Couplings caused by
insufficient distance bet-
ween neighbouring
loops
Verification: the minimum distance between neighbouring loops has to be half the length of the parallel loop
edges.
Note: There is no minimum distance between the loops of one detector for multiplex detectors (VEK
M...)
Remedye: Install loops with a greater distance in between.
Interference at the loop Verification: check fluctuations in detuning mode with the helo of diagnostic device VEK FG2. They must
not
exceed 2 increments.
Remedy: - choose another frequency level.
-Use of an 8-loop makes the loop more insensitive to interferences.
-Note: compared to square loops, 8-loops reduce the responsiveness of the system!
Interference at the loop
feeder Verification: check fluctuations in detuning position with the help of diagnostic device VEK FG2 .
Fluctuation
must not exceed 2 increments.
Remedy: - the loop feeder has to be thoroughly twisted (min. 25 turns/m).
- do not install the loop feeder together with other live leads in one cable pit.
- carry out interference elimination (toroidal core, filter, etc.).
Interference at the
detector Verification: check fluctuations in the detuning position witht the help of diagnostic device VEK FG2. They
must
not exceed 2 increments.
The detector must not align automatically when switching loads (e.g. barrier motor).
Remedy: - connect the detector’s supply main to another phase.
- carry out interference elimination (toroidal core, filter, etc.).
Insufficient mechanical
solidity of the loop Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in
detuning position with regard to possible frequency jumping or permanent detuning.
Note: changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative detuning,
the
detector becomes more insensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any
deformations in the loop geometry when crossing it with a vehicle.
- the loop must not move compared to the ground armouring.
- for installation under paving stones, please always use finished loops.

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 17
Metallic objects within
loop area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding)
Detector does not respond to lorries
Possible reasons Measures
Sensitivity is too low Verification: cross the loop with a lorry and check the detuning with diagnostic device VEK FG2.
Due to the great distance between the bottom of the car body and the loop, the detuning
caused by
Lorries is lower than the one caused by passenger cars. Therefore, the responsiveness of the
Detector has to be higher.
Remedy: increase sensitivity
Unfavourable loop
geometry Verification: cross the loop with a lorry and check detuning with diagnostic device VEK FG2 . Remedy: choose a loop geometry which is completely covered by the vehicle.
Insufficient mechanical
loop solidity Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in detuning
Position with regard to possible frequency jumping or permanent detuning.
Note: Changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative
detuning, the
detector becomes more sensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any defor-
mations in the loop geometry when crossing it.
-The loop must not move compared to the ground armouring.
-For installation under paving stones, please do always use finished loops.
Influences caused by
armouring or metal foil Verification: cross the loop with a vehicle and check detuning with the help of diagnostic device VEK FG2 . Note: the loop is deadened by strong armouring or metal foil which is located in the concrete floor under
the loop. Such loops have a reduced sensitivity.
Remedy: - influences caused by the armouring may be leveled out to a certain extent by increasing the
detector’s responsiveness.
- spare the metal foil in the loop area.
Metallic objects in loop
area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding
Detector only responds short-term or not at all
Possible reasons Measures
Sensitivity has not been
adjusted Verification: cross the loop with a vehicle and check detuning with diagnostic device VEK FG2..
Remedy: Adjust the sensitivity of the detector. (see charts under „Selection of sensitivity“)
Unfavourable loop
geometry Verification: cross the loop with a vehicle and check the detuning with the help of diagnostic device VEK FG2 .
Remedy: choose a loop geometry, which is completely covered by the vehicle.
Loop area is too big Verification: cross the loop with a vehicle and check detuning with the help of diagnostic device VEK FG2.
Remedy: - install a smaller loop.
- choose another loop geometry.
- interconnect several smaller loops. Caution: sensitivity loss !

operating instructions VEK FG2-1
18 12/99 FEIG ELECTRONIC GmbH
Influences caused by
armouring or metal foil Verification: cross the loop with a vehicle and check the detuning with diagnostic device VEK FG2. Note: the loop is deadened by strong armouring or metal foil which is located in the concrete floor
under the loop. Such loops have a reduced sensitivity.
Remedy: -to a certain extent, the influences caused by strong armouring or metal foil in the concrete floor
may
be leveled out by increasing the detector’s responsiveness.
-spare the metal foil in the loop area.
Wrong alignment Verification: the diagnostic device VEK FG2 shows a permanent negative detuning.
Detector has been aligned with the loop being occupied and deadened.
Remedy: re-align the detector with the loop not occupied.
Insulation fault Verification: check insulating resistance of the loop and feeder between feeder end and earth potential with
the
help of an insulation tester, such as the Isolavi. The insulating resistance has to be higher than
2 M.
Remedy: eliminate the source of errors, install new loop resp. loop feeder
Loop feeder is too long Verification: check feeder length between detector and induction loop according to detector data sheet.
Remedy: -install interstage transformer VEK ANPASS between detector and loop feeder.
- place the detector resp. loop elsewhere.
Insufficient mechanical
loop solidity Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in
detuning position with regard to possible frequency jumping or permanent detuning.
Note: changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative detuning,
the
detector becomes more insensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any
deformations in the loop geometry when crossing it with a vehicle.
- the loop must not move compared to the ground armouring.
- for installation under paving stones, please always use finished loops.
Metallic objects in loop
area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding)

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 19
Detector re-aligns automatically
Possible reasons Measures
Interferences during the
switching of loads Verification: check, whether the detector aligns automatically while switching contactors, motors or other loads.
Remedy: - connect the detector’s supply main to another phase
- try to optimize the wiring
- carry out interference elimination measures
Interferences a at the
loop
Verification: check fluctuations in detuning mode with the helo of diagnostic device VEK FG2. They must
not
exceed 2 increments.
Remedy: - choose another frequency level.
-Use of an 8-loop makes the loop more insensitive to interferences.
Note: compared to square loops, 8-loops reduce the responsiveness of the system!
Interferences at the loop
feeder
Verification: check fluctuations in detuning position with the help of diagnostic device VEK FG2 .
Fluctuation
must not exceed 2 increments.
Remedy: - the loop feeder has to be thoroughly twisted (min. 25 turns/m).
- do not install the loop feeder together with other live leads in one cable pit.
Interferences at the
detector
Verification: check fluctuations in the detuning position witht the help of diagnostic device VEK FG2. They
must
not exceed 2 increments.
The detector must not align automatically when switching loads (e.g. barrier motor).
Remedy: - connect the detector’s supply main to another phase.
Insufficient mechanical
loop solidity Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in
detuning position with regard to possible frequency jumping or permanent detuning.
Note: changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative detuning,
the
detector becomes more insensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any
deformations in the loop geometry when crossing it with a vehicle.
- the loop must not move compared to the ground armouring.
- for installation under paving stones, please always use finished loops.
Metallic objects in loop
area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding)
Unstable base frequency
Possible reasons Measures
Interferences at the loop Verification: check fluctuations in detuning mode with the helo of diagnostic device VEK FG2. They must
not
exceed 2 increments.
Remedy: - choose another frequency level.
-Use of an 8-loop makes the loop more insensitive to interferences.
Note: compared to square loops, 8-loops reduce the responsiveness of the system!
Interferences at the loop
feeder Verification: check fluctuations in detuning position with the help of diagnostic device VEK FG2 .
Fluctuation
must not exceed 2 increments.
Remedy: - the loop feeder has to be thoroughly twisted (min. 25 turns/m).
- do not install the loop feeder together with other live leads in one cable pit.
Interferences at the
detector Verification: check fluctuations in the detuning position witht the help of diagnostic device VEK FG2. They
must
not exceed 2 increments.
The detector must not align automatically when switching loads (e.g. barrier motor).
Remedy: - connect the detector’s supply main to another phase.

operating instructions VEK FG2-1
20 12/99 FEIG ELECTRONIC GmbH
Detector responds even if loop is not covered
Possible reasons Measures
Couplings caused by
insufficient frequency
separation
Verification: check frequencies of all loops with diagnostic device VEK FG2. Frequency separation of
neighbouring loops has to be at least 5 kHz (VEK V..-types) resp. 10 kHz (VEK M..-types).
Note: For multiplex detectors (VEK M...), frequency separation is not necessary for loops of one
detector.
Remedy: re-adjust loop frequencies and check with diagnostic device VEK FG2.
Couplings caused by
insufficient distance
between neighbouring
loops
Verification: the minimum distance between neighbouring loops has to be half the length of the parallel loop
edges.
Note: There is no minimum distance between the loops of one detector for multiplex detectors (VEK
M...)
Remedye: Install loops with a greater distance in between
Interferences at the loop Verification: check fluctuations in detuning mode with the helo of diagnostic device VEK FG2. They must
not
exceed 2 increments.
Remedy: - choose another frequency level.
-Use of an 8-loop makes the loop more insensitive to interferences.
Note: compared to square loops, 8-loops reduce the responsiveness of the system!
Interferences at the loop
feeder Verification: check fluctuations in detuning position with the help of diagnostic device VEK FG2 .
Fluctuation
must not exceed 2 increments.
Remedy: - the loop feeder has to be thoroughly twisted (min. 25 turns/m).
- do not install the loop feeder together with other live leads in one cable pit.
Interferences at the
detector Verification: check fluctuations in the detuning position witht the help of diagnostic device VEK FG2. They
must
not exceed 2 increments.
The detector must not align automatically when switching loads (e.g. barrier motor).
Remedy: - connect the detector’s supply main to another phase.
Interferences caused by
compensating current in
the armouring or other
metal parts
Verification: use the diagnostic device VEK FG2, position detuning , to check frequency stability.
Fluctuations must not exceed 2 increments.
Remedy: choose the greatest possible distance between loops and armouring. The greater the distance
between armouring and loops, the lesser the influence on the loop.
In some unfavourable cases, the armouring has to be spared in the loop area.
Insufficient mechanical
loop solidity Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in
detuning position with regard to possible frequency jumping or permanent detuning.
Note: changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative detuning,
the
detector becomes more insensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any
deformations in the loop geometry when crossing it with a vehicle.
- the loop must not move compared to the ground armouring.
- for installation under paving stones, please always use finished loops.
Metallic objects in loop
area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding)

VEK FG2-1 operating instructions
FEIG ELECTRONIC GmbH 12/99 21
Detector falls off in spite of the loop being occupied
Possible reasons Measures
Insufficient stop period Verification: check the adjusted stop period
Remedy: increase the detector’s stop period resp. set on infinite.
Insufficient mechanical
loop solidity Verification: tap the surface above the loop with a beam and observe diagnostic device VEK FG2 in
detuning position with regard to possible frequency jumping or permanent detuning.
Note: changes in the loop geometry may cause positive as well as negative detuning of the detector.
Positive detuning may lead to a permanent seizure of the detector. In case of negative detuning,
the
detector becomes more insensitive. Extreme frequency jumps may lead to a re-alignment of the
detector.
Remedy: -please make sure that the loop is of sufficient mechanical solidity; there must not be any
deformations in the loop geometry when crossing it with a vehicle.
- the loop must not move compared to the ground armouring.
- for installation under paving stones, please always use finished loops.
Metallic objects within
loop area Verification: use diagnostic device VEK FG2 in detuning position to check frequency fluctuations and
-jumps caused by movements of the metallic object.
Note: If metallic objects (e.g. manhole covers, grates, loose gates etc.) are surrounded by the loop,
their
movements may cause detunings of the resonant circuit. Should there be permanent, negative
frequency changes, the system may not recognize vehicles which do only cause minor detuning.
Remedy: - re-install loop, so that the metallic object is now outside the loop field.
- replace the metallic object by a non-metallic one.
- prevent movements of the metallic object.
(if necessary, fix manhole covers and grates by welding)
The above chart does not claim to be complete. Further information regarding the loop/detector system may
be found in our brochure "Vehicle recognition with the induction loop detector".
9 Index
Alignment 12; 18
to align, detector 12
Number of vehicles 9
Automatic cutoff 9
to adjust detector 12
Sensitivity 7; 12; 15; 17
Error messages 9
Base frequency 7; 8; 12; 19
Stop period 12; 21
Initiation 11
Increments 8; 9
Couplings 7
How to load the accumulator 7;
10
Delivery options 15
Reset 12
Loop installation 11
Malfunctions 11
Survey of detectors 14
Cross-talk 16
Detuning 8; 9; 15
Number of turns 14