Introduction:The DB9 Tester is the easiest way for you to test the connection on any male or female 9 Pin Serial connections. This adapter allows you to monitor the status of your connections by marking them with LEDS, which flash when there is activity on the pins. This device is easy to install, it features a Plug & Play Easy test RS-232 Host to Device link.
Pin Assignments:

DB - 9 Pin assignment Pin1 / Pin8 : DCD IN
Pin2 / Pin3 : RXD IN
Pin3 / Pin2 : TXD OUT
Pin4 / Pin20 : DTR OUT
Pin5 / Pin7 : GND
Pin6 / Pin6 : DSR IN
Pin7 / Pin4 : RTS OUT
Pin8 / Pin5 : CTS IN
Pin9 / Pin22 : RI IN

Additional Features and Specifications:

RS-232 DTE connector : DB9 - M
RS-232 DCE connector : DB9 - F
Data rate : Up to 200 K bps
With GND & Shell Test's LED
Single / TTL out 1 - LED appear Green (V-)
Single / TTL out 0 - LED appear Red (V+)
Housing : Plastic
Weight : 55g
Dimensions (LxWxH) : 45 * 35 * 21 ( mm ) body

OS SupportWindows 98, Me, XP, 2000, 2003, CE, Vista, Windows 7, and Windows 8 Linux and Mac OS 10.X
Standard RS-232 DTE & DCE Interface with DB-9 / F & DB-9 / M Connectors
RS-232 DB-9 / DB25 Pin assignment No Power required
Easy to install , Plug & Play
Double colors LED for easy cheeking of data transfer & receive
Works with Windows 7, 8, 10, Linux, Mac OS X