BB-232CDT - Serial Data Tap, RS-232, DB25 M to DB25 F plus DB25 F Monitor
The BB-232CDT has DIP switches that allow you to monitor the main Transmit and Receive lines individually or together. The male RS-232 connector on the top and the female RS-232 connector on the bottom are connected straight through, pin for pin. These connectors are used to connect the device – in series – with the RS-232 line to be tapped.