Omron B7A - Page 103

B7A
B7A
101
Peripheral Circuits of Modular Model
Input Interface Circuit
The modular model has a minimum ON discrimination voltage of 2.2
V and a maximum OFF discrimination voltage of 0.8 V, which are
suitable
for TTL circuits. If sensors are used for input, the following
input circuits are required.
Two-wire DC Sensor Input
If a two-wire DC sensor is used for input, current limit resistor R
1
and
leakage current diverter R
2
are required as shown in the diagram
below.
The following table lists R
1
and R
2
values for the E2E-XD-N
Two-wire DC Proximity Sensor (with a current leakage of 0.8 mA
maximum,
a residual voltage of 3 V maximum, and a minimum con -
trol
output current of 3 mA).
Input Interface (E2E-XD-N)
Supply voltage 12 V 24 V
R
1
1,800 Ω 5,600 Ω
R
2
820 Ω 820 Ω
R
1
R
2
+
–
IN
Two-wire DC
proximity sensor
Interior of B7A
Intemal circuit
Input with B7A and Common Power Supply
(12 to 24 VDC) (10-point Modular Model only)
The 10-point modular model has an input voltage range of 0 to 5
VDC.
If a common power supply is connected, current limit resistor
R
3
is required as shown in the diagram below . Use the following for -
mula
to calculate the value of R
3
.
R
3
= – 2,200 ( Ω)
Supply voltage V
S
(V) – 1.4 (V)
Input current (2 x 10
–3
(A))
Note: The 16-point module’ s input voltage range is 0 V to the
power supply voltage. Therefore no current limit resis -
tor
is required.
+
–
IN
Vs (12 to 24 VDC)
R
3
2.2 kΩ
Interior of B7A
Intemal circuit
Noise Protection Circuits
If there is a possibility of noise interference from the power supply , input, and/or output lines, add the following noise protection circuits.
Power supply noise protection circuit Input noise protection circuit Output noise protection circuit
12 to
24 VDC
R
C
+
+
–
B7A
R: 10 to 20 Ω
(1/8 W min.)
C: 33 µF min with a dielectric strength of 50 V min
+
–
IN
CV
R
B7A
V
1N
Input device
Photocoupler
C: 0.1 µF min.
R: Photocoupler input current limit resistor
Load
R
V
OUT
B7A
+
–
ZD
Photocoupler
R: Photocoupler input current limit resistor
ZD: V
ZD
= 36 V (with a power consumption
of 1 W min.)
C
: 33 µF min. with a dielectric strength o
f
50 V min.
B7A
–
IN
ZD
Input device
ZD: V
ZD
= 36 V
(with a power consumption of 1 W min.)
ZD
OUT
B7A
+
–
ZD: V
ZD
= 36 V
(with a power consumption
of 1 W min.)
Load