The 9PCDT allows an RS-232 port to tap into and check the data being transmitted between two other RS-232 ports. Switches make it simple to choose between monitoring the DCE or DTE port. The 9PCDT also allows the monitoring port to be either DTE or DCE. The DTE connector is male, and the DCE and TAP connectors are female. All nine lines are run through from the DCE to the DTE connectors. On the TAP connector RTS (pin 7) is tied to CTS (pin 8) and DSR (pin 6) is tied to CD (pin 1) and DTR (pin 4). Signal ground (pin 5) is tied into the signal ground for the DCE and DTE connectors.
9 PIN DATA TAP
