Omron Sysmac NX Series User Manual page 96

4 Installation and Wiring
 Relation between Input Current at Trigger Input Terminals and Sensor
Control Output (Load Current)
The trigger inputs of the High-speed Analog Input Units can detect sensor output ON only when the
following conditions are satisfied:
I (min) ≤ I
OUT
I (min): Minimum value of load current
OUT
I (max): Maximum value of load current
OUT
Use the following equation to calculate the input current:
I = I
in ON
Note At the trigger input terminals of the High-speed Analog Input Units, the input current does not increase
linearly for the input voltage. If you gradually raise the input voltage and once the input current reaches
I , the input current does not increase any further, and remains roughly constant even when the input
ON
voltage is raised.
When I is smaller than I
in
be calculated as follows: Select an appropriate bleeder resistor R so that both equations can be
satisfied.
R ≤ (V - V
CC
Rated power W of bleeder resistor ≥ (V
The voltages and currents related to the conditions for NPN type sensors are shown in the figure
below.
Two-wire sensor
The voltages and currents related to the conditions for PNP type sensors are shown in the figure
below.
4 - 28
≤ I (max)
in OUT
(min), connect a bleeder resistor R. The bleeder resistor constant can
OUT
)/(I (min.) - I )
R OUT ON
R
V
I I
CC
OUT in
V
R
NX-series Analog I/O Units User's Manual for High-speed Analog Input Units (W592)
2
- V ) /R × 4 [allowable margin]
CC R
IOV
Unit that can supply I/O power
to the NX bus
IOG
IOV
IN
High-speed Analog Input Unit
IOG