Around 3 years ago, I used a Proximity reader from HID which had 26 Bit Wiegand output. I just inverted the both outputs from the reader (using a 74HC14) and used them as inputs to INT0 and INT1 interrupts of 8051 and then did the rest in the software.

Here are some more links which could help you

http://www.internationalbarcode.com/app0012.pdf

http://www.paxton-access.co.uk/docs/data...bitwei.pdf

http://www.kerisys.com/pages/dow...cument.pdf

and

http://www.pcprox.com/Products/...heory.html


I hope it will help