Omron ZEN Operation Manual page 73

Wiring
Note
less than 0.8 mA. If the leakage current exceeds this value, insert a
bleeder resistor in the circuit to reduce the input impedance, as
shown in the following diagram.
The OFF voltage of the analog/digital input terminals on the CPU
Unit is 30 V DC. A 2-wire DC sensor can not be connected.
2-wire sensor, etc.
I: Device's leakage current (mA)
R: Bleeder resistance (kΩ)
W: Bleeder resistor's power rating (W)
R =
I × L c − 5.0
The equations above were derived from the following equations:
Input voltage (24)
R ×
Input Current (I c )
I ×
Input voltage (24)
R +
Input Current (I c )
Input voltage (24)
W ≥
R
Refer to page 123 Input Specifications for details on the values L
The input impedance, input current, and OFF voltage may vary depending on
the input being used.
Input power
supply
R
Bleeder
resistor
L
I
E
L c × 5.0
kΩ max.
≤ OFF voltage (E c : 5.0)
× Input voltage (24) × tolerance (4)
Section 2-2
ZEN
: ZEN's input impedance (kΩ)
C
: ZEN's input current (mA)
C
: ZEN's OFF voltage (V) = 5.0 V
C
2.3
W = W min.
R
, I , and E .
C C C
49