10.6  Input Signal (NPN) 
  When using an external power supply 
Input signals are treated as active when the photocoupler is ON. 
When using an external  power supply, the input signals become active when the  input  pin and  the 
external power supply ground are ON. 
 
  When using an internal power supply (optional) 
Input signals are treated as active when the photocoupler is ON.   
Using an internal power supply, the input signals become active when the input pin and the COM- pin 
are shorted. 
 
 
 
 
 
 
 
 
 
 
 
 
 
Assigning the wrong wiring to the I/O can damage the internal circuits. 
 
External Power Supply DC24V 
(DC24V) 
#genIn8 
 
(GND) 
Internal Power Supply DC24V 
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