C850
23
532015 - Rev.B
LOOP 1
LOOP 2
mm
mm
T
ranslation of the original instructions
ENGLISH
11.5.5 SETTING THE INTEGRATED LOOP DETECTOR
The E850 features an integrated metal mass detector for the
induction detection of vehicles.
Specifications:
•
Galvanic separation between the detector electronics and
the loop electronics
•
automatic system alignment immediately following activation
•
continuous resetting of the frequency drifts
•
sensitivity independent of loop inductivity
•
loop work frequency adjustment
•
occupied loop message with LED visualisation
•
loop status addressable on OUT 4
Connection:
Connect the detection loops as shown in figure 28:
- Terminals 1 - 2 for LOOP 1 =
loop with gate opening function;
- Terminals 3 - 4 for LOOP 2 =
loop with closing and/or safety
function.
To enable operation of the connected loops, enter basic pro-
gramming level mode and set the parameters
L1
and
L2
on
Y
, consistent with the connected loops. If only one loop is
installed, enable only the corresponding parameter.
The loop detector operating status is shown using the display
decimal points when the automated system status is visualised
(parameter
St
).
CALIBRATION
Each time the E850 board is powered, the display shows the
automated system status and the integrated loop detector performs
the auto-calibration of the connected loops. Therefore, perform an
auto-calibration of the E850 for at least 5 seconds.
Calibration is signalled by the two flashing decimal points, as
shown in figure 43.
If one or both magnetic loops are not
installed, the loop detector remains
in constant calibration mode without causing problems
to board operation. Therefore, during visualisation of
the automated system status, one or both decimal
points will flash constantly.
Once calibration is completed, the decimal points represent the
loop statuses:
Decimal point ON = Loop ENGAGED
Decimal point OFF = Loop CLEAR
Decimal point FLASHING = Loop NOT CONNECTED or
CALIBRATING
Fig. 43
ADJUSTING THE SENSITIVITY
By adjusting the sensitivity you determine the variation of
inductivity, for each channel, which a vehicle must cause in order
to activate the corresponding detector output.
Sensitivity is adjusted separately for each channel with the use
of the parameters
S1
and
S2
at basic programming level. See
section 11.5.1.
ADJUSTING THE HOLDING TIME
The holding time count starts when the loop is engaged.
When the time has elapsed, if the loop is still occupied, a new
automatic calibration is performed, in which the presence of the
metal mass on the loop no longer determines its engagement.
At the end of the new calibration the loop is considered “clear”.
The holding time can be adjusted using the parameters
h1
and
h2
in advanced programming mode.
See section 11.5.4.
ADJUSTING THE FREQUENCY and NEW BALANCING
The work frequency of each detector channel can be adjusted on
two levels using dip-switches DS1 (see fig.27).
DIP 1
ON = Loop 1 frequency LOW
OFF= Loop 1 frequency HIGH
DIP 2
ON = Loop 2 frequency LOW
OFF= Loop 2 frequency HIGH
When one of the dip-switches is changed, we recommend
performing a new calibration. If two loops are installed, select
different frequencies for each loop.
NOTES FOR MAKING THE LOOPS
The loop must be made at least 15 cm from fixed metal objects,
at least 50 cm from moving metal objects and no more than 5 cm
from the surface of the final paving.
Use a standard unipolar cable measuring 1.5 mm² in diameter (if
the cable is laid below ground level directly, it must have double
insulation). Make a preferably square or rectangular loop, by
preparing a cable runner in PVC or by tracing the paving as
shown in figure 44 (corners must be cut at a 45° angle to avoid
cable breaks). Lay the cable using the number of windings shown
in the table. The two ends of the cable must be twisted together
(at least 20 times per metre) from the loop to the detector. Avoid
splicing a cable (if necessary, weld the conductors and seal the
splice using a heat-shrinking sheath) and keep it separate from
the mains power lines.
Fig. 44
Loop
Perimeter
Nr. of
Windings
less than 3 m
6
from 3 to 4 m
5
from 4 to 6 m
4
from 6 to
12 m
3
more than
12 m
2
