NK823x Pin Assignment
Relay Output (X101)  | 
Pin  | Assignment  | Circuit  | 
|---|---|---|
1  | Common  | 
  | 
2  | NO output  | |
3  | NC output  | 
Inputs (X102)  | 
Pin  | Assignment  | Circuit 1 (Supervision of Internal Power Supply)  | Circuit 1 (Supervision of External Power Supply)  | 
|---|---|---|---|
1  | Input 1 (Mains failure) 1)  | 
  | 
  | 
2  | Input 2 (Battery fault) 1)  | ||
3  | Input 3 (Power supply fault) 1)  | ||
4  | Common  | ||
5  | + Val  | ||
6  | – Val  | 
1)  | The input signals can be used individually or combined together for power supply supervision application.  | 
Power Supply (X103)  | 
Power supply  | Pin  | Assignment  | 
|---|---|---|
Primary  | 1  | +  | 
2  | Earth  | |
3  | –  | |
N/A  | 4  | Not used  | 
N/A  | 5  | Not used  | 
Secondary (optional)  | 6  | +  | 
7  | Earth  | |
8  | –  | 
RS485 connectors (X104 and X105)  | 
Pin  | Assignment  | 
|---|---|
1  | RS485 +  | 
2  | RS485 –  | 
Ethernet Connections  | 
Pin  | Assignment  | 
|---|---|
1  | TX+  | 
2  | TX–  | 
3  | RX+  | 
4  | 
  | 
5  | 
  | 
6  | RX–  | 
7  | 
  | 
8  | 
  | 
RS232 Connections  | 
Pin  | Assignment  | |
|---|---|---|
  | COM 1-2  | COM 3-4  | 
1  | CD  | 
  | 
2  | RXD  | RXD  | 
3  | TXD  | TXD  | 
4  | DTR  | 
  | 
5  | GND  | GND  | 
6  | DSR  | 
  | 
7  | RTS  | 
  | 
8  | CTS  | 
  | 
9  | RI  | 
  | 
 
 
 