On the Data Tap 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 Data Tap in series with the RS- 232 line to be tapped. Either the Transmit Data from pin 2 or the Receive Data from pin 3 can be brought out to the Tap Connector. Pin 1, Protective Ground, and pin 7, Signal Ground, of all three connectors are interconnected.
The small switch is used to program the Tap Connector. The bottom two switches pick Receive Data (RD) or Transmit Data (TD) to be sent to the Tap Connector. (See the markings near the switch.) When the RD switch is on, only mainline Receive Data is sent to the Tap Connector. When the TD switch is on, only mainline Transmit Data is sent to the Tap Connector. When both switches are on, both the Transmit Data and the Receive Data are sent to the Tap Connector.
The top two switches are used to select which pin on the Tap Connector the data will be sent. If the switch marked 2 is on, the data will be connected to pin 2 (Transmit Data) of the Tap Connector. If the switch marked 3 is on, the data will be connected to pin 3 (Receive Data) of the Tap Connector.
On the Tap Connector pin 4 (Request To Send) and pin 5 (Clear To Send) are connected together. Also pin 6 (Data Set Ready), pin 8 (Carrier Detect), and pin 20 (Data Terminal Ready) are connected together. This is required to enable the device connected to the Tap Connector.