Omron NX-OD5256 User Manual

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4 Installation and Wiring
NX-series Digital I/O Unit User’s Manual (W521)
4-4 Wiring Examples
4
4-4-1 Wiring the Input Units
(b) Relation between input current to the DC Input Unit and sensor control output (load current)
The DC Input Unit cannot detect sensor output ON unless the following conditions are satisfied:
I
OUT
(min) ≤ I
in
≤ I
OUT
(max)
I
OUT
(min): Minimum value of load current
I
OUT
(max): Maximum value of load current
Use the following equation to calculate the input current of the resistance input.
I
in
= (V
CC
- V
R
- 1.5 [internal residual voltage of DC Input Unit]) / R
IN
Use the following equation to calculate the input current of the constant current input.
I
in
= I
ON
Note For constant current input type Input Units, the input current does not increase linearly for the input volt-
age. If you gradually raise the input voltage and once the input current reaches I
ON
, the input current
does not increase and remains roughly constant even when the input voltage is raised.
When I
in
is smaller than I
OUT
(min), connect a bleeder resistor R. The bleeder resistor constant can
be calculated as follows: Select an appropriate bleeder resistor R so that both equations can be sat-
isfied.
R ≤ (V
CC
- V
R
) / (I
OUT
(min) - I
ON
)
Rated power W of bleeder resistor ≥ (V
CC
- V
R
)
2
/ R × 4 [allowable margin]

Omron NX-OD5256 Specifications

General

Brand	Omron
Model	NX-OD5256
Category	I/O Systems
Language	English