2-18          
(3) CN1 Interface Circuit and Wire Mode:  
The diagram below introduces all interface circuit of CN1 and wire-method of host controller.  
(a)  Digital input interface circuit (IO1): 
Digital input interface circuit can be operated by relay or collector transistor circuit. The relay should be the 
 low electric current, in order to avoid the faulty contacting. External voltage: 24V.  
Internal 24V Power  External 24V Power 
 
 
  (b)  Digital Output Interface Circuit (IO2):  
When using external power, please attention to the power polarity. Adverse polarity will case circuit 
damage. Digital output is “Open Collector”. The maximum of external voltage is 24V; and the maximum 
electric current is 10mA.  
Internal 24V Power  External 24V Power