5-37
5 Installation
CJ2 CPU Unit Hardware User’s Manual
5-3 Wiring
5
5-3-6 Wiring with Ethernet Cable (CJ2H-
CPU6@-EIP only)
• Relation between current when the PLC is OFF and sensor leakage current:
I
OFF
≥ Ileak
Connect a bleeder resistor if I
leak
is greater than IOFF. Use the following equation to calculate the
bleeder resistance constant.
R ≤ (R
IN × VOFF)/(Ileak × RIN − VOFF
)
Power W ≥ (VCC − VR)
2
/R × 4 [allowable margin]
• Precautions on Sensor Surge Current
An incorrect input may occur if a sensor is turned ON after the PLC has started up to the point
where inputs are possible. Determine the time required for sensor operation to stabilize after the
sensor is turned ON and take appropriate measures, such as inserting into the program a timer
delay after turning ON the sensor.
z Example
In this example, the sensor's power supply voltage is used as the input to CIO 000000 and a 100-ms
timer delay (the time required for an OMRON Proximity Sensor to stabilize) is created in the pro-
gram. After the Completion Flag for the timer turns ON, the sensor input on CIO 000001 will cause
output bit CIO 000100 to turn ON.
V
R
R
V
CC
R
IN
VCC:
V
ON:
V
OFF:
I
ON:
I
OFF:
R
IN:
V
R:
I
OUT:
I
leak:
R:
Sensor output residual current
Sensor control current (load current)
Sensor leakage current
Bleeder resistance
Power voltage
PLC ON voltage
PLC OFF voltage
PLC ON current
PLC OFF current
PLC input impedance
Two-wire sensor
DC Input Unit
TIM
0000
#0001
000000
TIM0000 000001
000100
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