Advanced Tubular Loopback Tester Software

The Loopback Tester software is designed to allow you to test RS-232 cables and connectors with only one computer using a loopback connector. A "loopback connector" is a serial connector usually in DB9 form that loops various signals received in the connector back to the signals normally sent out from other computers. This is how the loopback connector is wired:

INCOMING Signals		OUTGOING Signals
The RX (Receive pin)		is jumped to the TX (Send pin)
The CTS (Clear to Send pin)		is jumped to the RTS (Request to Send pin)
In many loopback connectors, the DSR (Data Set Ready) and DCD (Carrier Detect)		are jumped to the DTR (Data Terminal Ready)

This forms a complete circuit for testing the original COM port, and all the important connectors and cable in between.

So a loopback tester is used to test an COM port cable and connectors with a single computer. The loopback tester is also used to test Benderlink Ethernet Modules. Here are a few images showing various states of the Loopback Tester software in action.

This screen shows all the controls illuminated at the same time. As the loopback "passes" the test, the Pass bars gets longer and the Failure bars gets shorter.
This screen shows both the transmit/receive and Request to Send (RTS) and Clear to Send (CTS)pins passing