NAiS FP Series User Manual page 63

Installation and Wiring
Precaution when using LED - equipped limit switch
If the input of PLC does not turn off because of the leakage current from the LED-
equipped limit switch, the use of a bleeder resistor is recommended, as shown below.
LED -
equipped
r
limit switch
r: Internal resistor of limit switch (kΩ)
Figure 45: FPΣ Precaution when using LED- equipped limit switch
The off voltage of input is 2.4 V, therefore when the power supply voltage is 24 V, select the
bleeder resistor "R" so that
the current will be greater than I =
The resistance R of the bleeder resistor is: R
The wattage W of the resistor is: W =
In the actual selection, use a value that is 3 to 5 times the value of W.
5 - 14
Input terminal
Bleeder
R
resistor
COM
Power supply for input
24 - 2.4
r
(Power supply voltage)
FPΣ
13.44
(kΩ)
5.6 x I - 2.4
2
R
FPΣ