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Information about the Wiegand Protocol used in security systems

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Newbie level 6
May 17, 2001
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Does anybody have any information on the Wiegand Protocol used in security systems? I have noticed that there are a few different implementations of the protocol but I can't find any information on the net.

Is there a specification available, and where can I get hold of it?
Can somebody please help?

TheBoss :(

wiegand protocol specification

Come on guys 26-bit wiegand? 34-bit wiegand? Doesn't anybody know anything about these protocols? :cry:

I really appreciate any help...

TheBoss :?

weigand protocol

may this link help you
**broken link removed**

Fire in the Wire

wiegand 26 protocol


it is a 3 wire (GND, DATA0, DATA1):

0's are impulses on DATA0 line
1's are impulses on DATA1 line

data bits are prefixed and postfixed with parity
length of data bits chunk can vary from 24-40 bits

i have somewhere in the archive my very old
asm implementation for atmel (51 core)
if you are interested ...

wiegand protocol pdf

It is a protocol that is used in "Access Control Systems" mostly the wireless ones, the Door reader reads induces electric field throug its Antenna when the card is in the coverage field, it returns back a certain number that is the card number.
Card Numbers can be formatted in many formats like the Wiegand and 35 system
The wiegand-26- as an example splits the 26 bits into two groups of 13 bits
the first group is used as a group identifier that all users within a corporate share, the other is user specific

wiegand 34

I'm trying to interface a wiegand reader with a microchip micocontroller,I was reading the posts but I still can't get it,in datao I get the '0' and data1 the '1',has anyone a timimg diagram to understand how to read it??
thanks a lot

wiegand protocol


You no need to see the timing digrame, you can used the interrup base, if u using the PIC16f84 you can used the portb 4:7 as input and setting as interrup base port.

good luck

wiegand protokoll

Wiegand Data Format
**broken link removed**

Re: Wiegand Protocol

iam using weigand protocol for accessing Card readers,can anyone help what is the maximum lenght shuold i connect my controller away from reader.i have connected about 20m distance between controller and reader,and used switching supply for the supply.iam getting a wrong data when i show a configured data.plz help me guys.

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