The RS232 testprogram checkes the data lines (Tx/Rx) and the handshake connections (RTS/CTS, DTR/DSR) in a Com-port.

A loop-back adapter is needed for this test to work, and it is made with a female 9-pin Sub-D, where the following connections are made:

If you computer has a 25-pin connector, make a loop-back adapter with the following connections:

Guide / FAQ:

The program should be strait forward to use, and all buttons and checkboxes, should be more or less self-explanatary, or show a tooltip.
Just select the tests you want, and press the Start button.
The test should take less than 10 secs. to complete.
To force the selection of Com-port 1, press the Del-key within 0.5sec. after the testprogram has been started.

Version Log:




- Same Comm-event not repeasted in results-list.
- When illegal Com-port is selected, it is automatically changed to Com1.
- Default baudrate changed 38400.
- Baudrates 57600 and 115200 added.
- Close/Open-port test added.
- More test-times are calculated and shown.
- Windows is "restored" when error in test occurs.


- First official released version


Download newest version by right clicking here (size 1.5Mbyte) and select "Save As".
Unpack the zip-file and run Setup.exe which install the program, and adds it to the Start-menu.

The program can be uninstalled with "Add/Remove Programs" in the control panel.

The program has been made with Visual Basic, and all necessary libraries (DLL & OCX) should be included in the installation.
If you think that all the necessary libraries are already installed on your PC, or you just want to update an older version, you can download RS232 Testprogram (size 76kbyte), and install it manually (just copy it to a directory and run it).