Example
Connection to a PLC
In this example, the above conditions are checked for when the PLC
model is the C200H-ID212, the Proximity Sensor model is the E2E-
X7D1-N, and the power supply voltage is 24 V.
Required Conditions
Connection to a PLC is possible if the specifications of the PLC and
the Proximity Sensor satisfy the following conditions. (The meanings
of the symbols are given below.)
1. VON (14.4 V) ≤ VCC (20.4 V) – VR (3 V) = 17.4 V: OK
2. IOFF (1.3 mA) ≥ Ileak (0.8 mA): OK
1. The ON voltage of the PLC and the residual voltage of the Prox-
imity Sensor must satisfy the following.
VON ≤ VCC – VR
V
PC (4 V)]/RIN (3 kΩ)
3. ION = [VCC (20.4 V) – VR (3 V) –
≈ 4.5 mA
Therefore,
2. The OFF current of the PLC and the leakage current of the Prox-
I
OUT(min) (3 mA) ≤ ION (4.5 mA): OK
imity Sensor must satisfy the following.
VON: ON voltage of PLC (14.4 V)
I
OFF ≥ Ileak
I
I
ON: ON current of PLC (typ. 7 mA)
OFF: OFF current of PLC (1.3 mA)
(If the OFF current is not listed in the specifications, take it to be
1.3 mA.)
RIN: Input impedance of PLC (3 kΩ)
PC: Internal residual voltage of PLC (4 V)
3. The ON current of the PLC and the control output (IOUT) of the
Proximity Sensor must satisfy the following.
IOUT(min) ≤ ION ≤ IOUT(max)
V
VR: Output residual voltage of Proximity Sensor (3 V)
leak: Leakage current of Proximity Sensor (0.8 mA)
OUT: Control output of Proximity Sensor (3 to 100 mA)
CC: Power supply voltage (PLC: 20.4 to 26.4 V)
Values in parentheses are for the following PLC model and Proximity
Sensor model.
I
I
V
The ON current of the PLC will vary, however, with the power sup-
ply voltage and the input impedance used as shown in the follow-
ing equation.
I
ON = (VCC – VR – VPC )/RIN
PLC: C200H-ID212
Proximity Sensor: E2E-X7D1-N
■ Precautions for AC/DC 2-wire Proximity Sensors in Operation
Connection
Model
Connection type
Method
Correct
Description
DC 2-wire AND (serial connection)
The Sensors connected together must satisfy the
following conditions.
VS – N x VR ≥ Load operating voltage
N: No. of Sensors
VR: Residual voltage of each Sensor
VS: Supply voltage
Load
If each Proximity Sensor is not supplied with the
rated voltage and current, the indicator will not be lit
properly or unnecessary pulses may be output for
approximately 1 ms.
OR
The Sensors connected together must satisfy the
following conditions.
Correct
(parallel connection)
Load
N x i ≤ Load reset current
N: No. of Sensors
i: Leakage current of each Sensor
If the MY Relay, which operates at 24 VDC, is used
as a load for example, a maximum of four Proximity
Sensors can be connected to the load.
AC 2-wire AND (serial connection)
If 100 or 200 VAC is imposed on the Proximity
Sensors, VL (i.e., the voltage imposed on the load)
will be obtained from the following.
Incorrect
Load
VL = VS – (residual voltage x No. of Proximity
Sensors) (V)
Therefore, if VL is lower than the load operating
voltage, the load will not operate.
Correct
A maximum of three Proximity Sensors can be
connected in series provided that the supply voltage
is 100 V minimum.
Load
Load
V
s
× 100 V
E2E/E2E2 Cylindrical Proximity Sensor
37
OMRON [ OMRON ELECTRONICS LLC ]
