operating instructions
VEK FG2-1
8
12/99
FEIG ELECTRONIC GmbH
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
detuning
Maximum
detuning
Det. channel
Minimum
detuning
