DB9 Interface PIN No. Description 1 None 2 RX 3 TX 4 None 5 GND 6 None 7 IO Control restart when power off(customized) 8 None 9 None 15PIN Interface PIN No. Name 1 ONLINE_OUT None 2 RXD Electric Level Input 3 TXD 4 DTR None 5 GND Negative 6 DSR None 7 RTS None 8 CTS None 9 Power_SW None 10 TTL_RXD TTL Electric Level Input（ 11 TTL_TXD TTL Electric Level Output 12 485A RS485 Electric Level Input 13 485B RS485 Electric Level Output 14 USB+ None 15 USB- None 12 PIN Block Interface Description Electric Level Output PIN No. Name Description 1 V+ Positive 2 V- Negative 3 485_A RS485 Positive 4 485_B RS485Negative 5 RXD Electric Level Input 6 TXD 7 GND Negative 8 PWR Power Control Pin 9 RTS None(Extendable) 10 CTS None(Extendable) 11 ONL Online Pini 12 ACT None(Extendable) Electric Level Output 20PIN Interface PIN No. Name Description 1 PIN_1 I/O Input/Output Pin 2 PIN_2 I/O Input/Output Pin 3 PIN_3 I/O Input/Output Pin 4 PIN_4 I/O Input/Output Pin 5 PIN_5 None 6 PIN_6 I/O Input/Output Pin 7 PIN_7 None 8 PIN_8 I/O Input/Output Pin 9 None 10 TTL_RX 11 None 12 TTL_TX TTL Electric Level Output 13 GND Negative 14 232_RX RS232 Input 15 GND Negative 16 232_TX RS232 Output TTL Electric Level Input 17 +5V Power Positive 18 485_A RS485 Positive 19 +5V Power Positive 20 485_B RS485 Negative