Omron NX1P2 Series Hardware User Manual page 210

5 Installation and Wiring
I = (V − V
ON CC
When I is smaller than I
ON
can be calculated as follows:
R ≤ (V − V
CC
Power W of bleeder resistor ≥ (V
V : Input voltage of DC input
CC
V : Sensor's output residual voltage
R
I : Input current of DC input
ON
I : Sensor control current (load current)
OUT
R : Input resistor of DC input
IN
(c) Relation between OFF current of the DC input and sensor leakage current
I ≥ I
OFF leak
When I is greater than I
leak
Use the following equation to calculate the bleeder resistance constant.
R ≤ R × V
IN OFF
Power W of bleeder resistor ≥ (V
Two-wire sensor
V : Power supply voltage
CC
V : ON voltage of DC input
ON
V : OFF voltage of DC input
OFF
I : ON current of DC input
ON
I : OFF current of DC input
OFF
R : Input resistor of DC input
IN
(d) Precautions on sensor inrush current
An incorrect input may occur due to sensor inrush current if a sensor is turned ON after the DC
input section has started up to the point where inputs are possible.
5-66
- 1.5 [internal residual voltage of DC input]) / R
R
(min), connect a bleeder resistor R. The bleeder resistor constant
OUT
) / (I (min) − I )
R OUT ON
− V
CC
, connect a bleeder resistor R.
OFF
/ (I × R − V )
leak IN OFF
− V
CC
General digital input
and flag input
V R
R
V
CC
IN
2
) / R × 4 [allowable margin]
R
2
) / R × 4 [allowable margin]
R
V : Sensor's output residual voltage
R
I : Sensor control output (load current)
OUT
I : Sensor leakage current
leak
R: Bleeder resistor
NX-series NX1P2 CPU Unit Hardware User's Manual (W578)