12
Slim Body Automatic Sensitivity Setting Photoelectric Sensor
SU-7
SERIES
SH
SERIES
PRECAUTIONS FOR PROPER USE
Amplifier
Wiring
• The self-diagnosis output does not incorporate a short-
circuit protection circuit. Do not connect it directly to a
power supply or a capacitive load.
Sensitivity setting
●
Normal sensitivity setting
●
Sensitivity for detecting minute differences
Setting for minute detection is possible just
by pressing
a button once without the object being present
.
For detecting
a tiny object
By pressing either ON or OFF button for 3 sec. or more, the threshold level is
set 15 % either lower or higher
than the object absent level as
shown in the right figure.
Please note that the output
operation cannot be reversed.
For example, press the ON
button for detecting a tiny object.
Background
Threshold
level
15 %
15 %
ON
OFF
100 %
Press OFF button for 3 sec. or more
Press ON button for 3 sec. or more
OFF
ON
0
Threshold
level
Object absent
level
High
Low
Incident ligh
t
intensit
y
Setting procedure
For stable detection of an object
without detecting the background
Limit sensitivity setting
●
For applications in which beam intensity fluctuates
Setting procedure
If the incident light is stable in either the object present or object absent
state, by shifting the threshold level towards this state, stable sensing
is possible even if the incident light is unstable in the other state.
The setting level is the same as for limit sensitivity setting. However,
since the operating level is shifted after the normal sensitivity setting,
output operation is selectable.
Press the sensitivity setting button which was pressed in the stable
light received condition. For example, for a diffuse reflective type
sensor, in case a background object is present, press the button
which was pressed with only the background object being sensed.
Background
ON
ON input
Shift
OFF 100 %
0
15 % approx. OFF input
Threshold level
before shift
Threshold level
after shift
Unstable
light intensity
Stable
light intensity
Incident light intensity
High
Low
Remote sensitivity selection function (SU-79 only)
•
SU-79
can store four channels of sensitivity levels, which
can be selected as per your requirement.
Designate the channel that is to store the sensitivity by
making the remote sensitivity selection inputs 1 and 2
suitably High or Low.
Wiring
Black
Brown
Blue
Pink
Violet
Orange
0 V
Self-diagnosis output
Sensing output
+V
Remote sensitivity selection input 1
Remote sensitivity selection input 2
Signal condition
Low: 0 to 1 V
High: 4.5 to 30 V, or open
Input impedance: 10 kΩ
Channel selection
Remote sensitivity
selection input 1
Remote sensitivity
selection input 2
1
Low
Low
2
Low
High
3
High
Low
4
High
High
Input
Channel
Sensitivity shift
Without
detecting
an object
While detecting
an object
OFF input
Threshold
level
ON input
High
Low
Incident ligh
t
intensity
Standard setting
●
Maximum sensitivity setting
*How to set sensitivity with external inputs
Instead of pressing buttons, the sensitivity can be set with
the remote
sensitivity setting inputs
. (There is no external sensitivity shift mode.)
Setting procedure
The procedure is the same as for setting with sensitivity buttons, except that
instead of pressing the buttons, the remote sensitivity setting input wire is short-
circuited to 0 V. The mode selection switch is set to either the “SET” or “RUN” side.
Self-diagnosis output
Sensing output
+V
Black
Brown
Blue
Pink
Violet
Orange
Remote sensitivity ON input
Remote sensitivity OFF input
0 V
• Time chart
The self-diagnosis output stays ON for 40 ms approx. after
ON input or OFF input is recognized by the sensor.
T
1
≥
1,000 ms, 3,000 ms
>
T
2
≥ 5 ms, T
3
≈ 310 ms, T
4
≈ 40 ms, T
5
≥
500 ms
Notes: 1)
Signal condition ... Low: 0 to 1 V, High: 4.5 to 30 V, or open Input impedance: 10 kΩ
2) Do not move the object, etc., or change the incident light intensity during T
3
.
ON
OFF
High
Low
High
Low
ON
OFF
T
1
T
2
T
3
T
4
T
5
T
2
T
3
T
4
Sensing
possible
(Note 2)
(Note 2)
Power supply
Remote sensitivity ON
input
Remote sensitivity OFF
input
Self-diagnosis output
(Answer back function)
Sensing output
If the difference between the ON and OFF levels (the difference
between incident light levels) is so small that stable detection is
not possible, it does not turn ON.
Remote sensitivity setting (SU-77 only)
The sensor recognizes the ON (object present) and OFF (object absent) levels by your pressing
of the buttons. The threshold level is automatically set
at the middle
between ON and OFF levels.
The maximum sensitivity
is set. Take
care that, in case of the diffuse reflective
type, if a background object is present,
the sensing output may turn ON even
without the sensing object.
High
Low
Threshold
level
Incident light intensity
Full power setting
