I read the interesting thread about PDA connections (and others)
preventing canopies from ejecting properly. I had considered putting
the PDA on the rail of the canopy. I had to rethink that.

One possible simple "break away" connector that was recently
recommended to me is a USB connector. They are simple, reliable, and
inexpensive gold plated slide connectors with four contacts. Purchase
a USB "extension cord" which has a male and a female connector (don't
ask me which is which). Cut the cord in the middle and splice it into
your serial connection to the PDA

All you need are four connections;

USB Pin 1 - Power +5Vdc - DB-9 pin 8 (may be vendor specific)
USB Pin 2 - Transmit - DB-9 pin 2
USB Pin 3 - Recieve - DB-9 pin 3
USB Pin 4 - Ground - DB-9 pin 5

Anyway, if you cut the PDA cradle cable, there should only be four
wires. Three may be a shield which you should connect to the shield of
the USB. Connect each to whatever you want at the USB connector and
call it the "fill in your last name proprietary cabling standard".

- John