UM_3201027_BIO100_EN_Rev00
18/20
8 Wiegand protocol description
The data is sent over the lines DATA 0 for the logic “0” and DATA 1 for the logic “1”.
Both lines use inverted logic, meaning that a pulse low on DATA 0 indicates a “0”
and a pulse low on DATA 1 indicates a “1”.When the lines are high, no data is being
sent. Only 1 of the 2 lines ( DATA 0 / DATA 1 ) can pulse at the same time.
Example: data 0010...
Data bit 0 = approximately 100 us (microseconds)
Data bit 1 = approximately 100 us (microseconds)
Time between two data bits: approximately 1 ms (millisecond). Both data lines (D0
and D1) are high.
Description for the 26 bits Wiegand format
Each data block consists of a first parity bit P1, a fixed 8 bits header, 16 bits of user
code and a 2nd parity bit P2. Such a data block is shown bellow:
Note
: Parity bits are calculated as follows:
P1 =
even parity calculated over the bits 2 to 13
P2 = odd parity calculated over the bits 14 to 25
Ejemplo:
170
31527
PP
Site code
User code
PI
1
1 0 1 0 1 0 1 0
0 1 1 1
1 0 1 1 0 0 1 0 0 1 1 1
0
Even
Parity
Bit
Odd
Parity
Bit
Site Code
User Code
