Omron C200HE-CPU11 Installation Manual page 84

Wiring
Precautions when
Connecting a Two-wire
DC Sensor
1, 2, 3...
72
For standard I/O Units:
The previous calculations are based on the following equations.
R
I
R )
Input voltage (24)
W w
When using a two-wire sensor with a 12-VDC or 24-VDC input device, check
that the following conditions have been met. Failure to meet these conditions
may result in operating errors.
1. Relation between voltage when the PC is ON and the sensor residual volt-
age:
x V
V – V
ON CC
2. Relation between voltage when the PC is ON and sensor control output
(load current):
(min) x I
I
OUT
I = (V – V
ON CC
When I is smaller than I
ON
bleeder resistor constant can be calculated as follows:
R x (V
– V
CC
Power W y (V
Note The residual voltage in the PC is 4.0 V for the following Units:
C200H-ID211/ID212/IM211/IM212/INT01
The residual voltage is 1.5 V for all other Units.
I = leakage current in mA
7.2
R =
––––––
2.4 x I – 3
2.3
W = W min.
–––
R
Input voltge (24)
Input current (10)
v OFF voltage (3)
Input voltage (24)
Input current (10)
Input voltage (24)
R
R
x I
(max.)
ON OUT
– 1.5 [PC internal residual voltage])/R
R
(min), connect a bleeder resistor R. The
OUT
)/(I (min.) – I )
R OUT ON
/R × 4 [allowable margin]
2
– V )
CC R
Section 3-2
kΩ max.
Tolerance (4)
IN