RS232 standard DB9 interface definition

        One 、RS232 DB9 Pin color and definition ：

         1- black 2- red 3- Brown 4- orange 5- yellow 6- green 7- blue 8- purple 9- white B: 1- black 2- Brown 3- red 4- orange 5- yellow 6- green 7- blue 8- purple 9- white  

         1. Carrier detection (DCD - Data Carrier Detect)

         2. Receive data (RXD - Receive Data)

         3. Send data (TXD - Transmit Data)

          4. The data terminal is ready (DTR - Data Terminal Ready)

         5. Signal ground (SG - System Ground)

         6. Data ready (DSR - Data Set Ready)

         7. Request to send (RTS - Request to Send)

         8. Clear send (CTS - Clear to Send)

         9. Ring to indicate (RI - Ring Indicator)

          Two 、DB9 Male head 、 Definition of female pin ：

         DB9 Male head / Pin type pin definition ：   Pin number    2       3      5    1、4、6       7、8

                                                  Signal definition RXD  TXD   The earth     

          notes ： This port can be connected to the equipment communicating with the computer    

         DB9 Female head / Hole pin definition ：   Pin number    2       3      5    1、4、6       7、8

                                                  Signal definition TXD  RXD   The earth  

          notes ： This port can be directly inserted into the COM mouth