You've been told that Category 5 (or better) rated twisted-pair cable is capable of handling normal RS232 data...right? But you're wondering how to hook up the DB connectors on your computer and peripheral to the cat5 cable.
Well, it's really simple; Just use these adapters and cat 5 patch cables. Assemble the appropriate adapter, plug it into your computer, plug one end of the patch-cable into the adapter, and the other into the cat 5 jack in the wall.
There isn't a standard (to our knowledge) on which cat5 wires go to which RS232 lines, so we just wire them in sequence like this:
|RS232 via Cat 5|
|8P8C Modular Jack Lead Color (Pin #)||DB9 Pin #||Signal Name||Source|
|Blue (1)||1||CD - Carrier Detect||Modem|
|Orange (2)||2||RXD - Receive Data||Modem|
|Black (3)||3||TXD - Transmit Data||Terminal|
|Red (4)||4||DTR - Data Terminal Ready||Terminal|
|Green (5)||5||Signal Ground|
|Yellow (6)||6||DSR - Data Set Ready||Modem|
|Brown (7)||7||RTS - Request To Send||Terminal|
|White (8)||8||CTS - Clear To Send||Modem|
Pin 9 is Frame Ground and is not required.
Note that with a few of these adapters in your toolkit, along with the usual supply of modular plugs, flat cable, and crimp-tool, you can make up your own RS232 cables as needed, always the perfect length!