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8
Synchronization input
Hold function of the analog output / switching off the laser diode
If 12-28 V is being applied to the sync input
,
then the sensor will hold the value of the current meas-
urement and will switch off the laser diode. It will wait until the sync input goes back to low (0 V)
before it starts a new measurement.
After every measuring cycle, the sensor will test the sync input again. After the high signal on the
synch. Input, it takes one cycle T1 until the hold situation is reached.
1
T
r
o
s
n
e
S
OWLF 4007 + 4013 + 4030 + 4060 FA S1 (L)
0.9 ms
s
m
7
.
2
OWLF 4100 FA S1 (L)
s
m
0
1
OWLF 4100 FS S1 (L)
T1
Low/high edge of sync signal
synch signal
0V
12-28 V
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Synchronizing several sensors
Several sensors may be synchronized using an external clock. The clock cycle must be low for less
than T1. The total time of a cycle must be at least T2. Within 20 cycles all sensors will be synchro-
nized.
3
T
2
T
1
T
r
o
s
n
e
S
10 ~ 250 µs
>1000 µs
5 µs ~ 450 µs
s
µ
0
0
8
1
~
s
µ
5
1
s
m
3
>
s
µ
0
5
2
~
0
1
s
m
7
~
1
.
0
s
m
5
.
0
1
>
s
m
3
~
1
0
.
0
If sensors are being synchronized this way, they all start their cycles at the same time. This means
they start to sample light together. The length of the sampling interval T3 or shutter time depends on
the surface. It may range from T3. White or gray objects reflect well enough to enable a less than half
the sampling of interval T3. Only very dark objects actually need the maximum sampling interval.
T1
T2
12-28V
0V
sync. signal
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Several sensors in non-synchronous use
To prevent a negative mutual influence, using several OWLF, the sensor can be used
with a non-synchronous trigger pulse. 12-28 V must be applied to the sync input, so that the laser will
be turned off. The following timing has to be obtained (S1 = sensor 1, S2 = sensor 2).
analog output S1
t1
0 V
12-28 V
synch. input S1
4 mA
20 mA
0 V
12-28 V
4 mA
20 mA
t2
synch. input S2
analog output S2
Seite / Page 36
t1 is the max. time after a high signal on the synch. input of S1 until the analog value will be held.
This value will be held as long the signal on the synch. input is high.
The min. time between the high signal of S1 and the low signal of S2 is t1, also. In this case, an
optical influence between the sensors is not possible.
t2 is the time until the analog signal is ready after a low signal on the synch. input of S2. This time
depends on the reflectivity of the object and if the reflectivity changes during the hold time.
Input circuit
2
t
1
t
r
o
s
n
e
S
< 0.9 ms
0.5 ~ 2.7 ms
s
m
1
.
8
~
5
.
0
s
m
7
.
2
<
s
m
0
1
~
3
s
m
0
1
<
27k
Ω
10k
Ω
sync in
low: 0 .. 2V
high: 12 .. 28V
3V3
OWLF 4007 + 4013 + 4030 + 4060 FA S1 (L)
OWLF 4100 FA S1 (L)
OWLF 4100 FS S1 (L)
OWLF 4007 + 4013 + 4030 + 4060 FA S1 (L)
OWLF 4100 FA S1 (L)
OWLF 4100 FS S1 (L)