User's Manual

98
WIEGAND DATA
3726 34
31 2
The 26 Bit Wiegand Data Output From The EM Cards
26-bit EM Card is the most popular one on the market. Almost all the controllers can use the 26-bit
standard format.
A 26 bit Wiegand protocol for card reading has 1 first parity bit, 24 bits of the Card ID, and 1 stop
bit for a total of 26 bits. The first parity bit is an Even parity bit calculated from the first 12 bits of
the code and the trailing parity bit is an Odd parity bit from the last 12 bits. The data transmitted
is in Hex Binary codes.
Each EM card or Keyfob is marked with an unique ID in Decimal Digits that is the code read by the
reader. The EM Card is also marked with a “3 digit + 5 digit” code that are the site code and ID
number arrangement of the Wiegand data.
EXAMPLE:
a) The Code Marked on One of The EM Cards:
The Timing and Electrical Manner of The Wiegand Data Output
Wiegand is a common medium in the communication between readers and controller in access
control. The Wiegand data from the keypad unit provides a level of compatibility for readers and
controller that can be used by consultants in custom project development.
The Wiegand interface uses three wires, one of which is a Common Ground and two of which are
data transmission wires called DATA 0 and DATA 1. When no data is being sent both DATA 0 and
DATA 1 are at high voltage. When a “0” is sent the DATA 0 is at low voltage while the DATA 1 stays
at a high voltage. When a “1” is sent DATA 1 is at the low voltage while DATA 0 stays at the high
voltage.
The high voltage level in the keypad unit is +5VDC to accommodate for long cable runs
(approximate 500 feet) from it to the associated controller typically located in a secure closet.
50 uS pulse
Data 0 Line
2 mS pulse interval
Data 1 Line
0 1 0 1
+5V
0V
+5V
0V
Wiegand Data 26-Bit, 34-Bit or 37-Bit Selection Jumper
The Wiegand data output can be selected to 26-bit, 34-bit or 37-bit standard format with the
jumper.
1) 26-Bit Wiegand Data Output
Bit 1 : Even Parity Bit (bit 2 – bit 13)
Bit 2 – Bit 25 : 24 Bit ID Number
Bit 26 : Odd Parity Bit (bit 14 – bit 25)
2) 34-Bit Wiegand Data Output
Bit 1 : Even Parity Bit (bit 2 – bit 17)
Bit 2 – Bit 33 : 32 Bit ID Number
Bit 34 : Odd Parity Bit (bit 18 – bit 33)
3) 37-Bit Wiegand Data Output
Bit 1 : Even Parity Bit (bit 2 – bit 19)
Bit 2 – Bit 36 : 35 Bit ID Number
Bit 37 : Odd Parity Bit (bit 19 – bit 36)
WIEGAND OUTPUT FORMATS (AR-2802A ONLY)
The ID Code to be read for Wiegand Output The Code does not belong to this system
0006613779 008,18789
100,60179
The Site Code and the ID number
The Code in Decimal Number : 6 6 1 3 7 7 9
The Code 6 6 1 3 7 7 9 Equivalent to Hex Number : 6 4 E B 1 3
b) Each Hex Number Consists of 4 Bits, Total 26 Bits of Wiegand Data Output from Card Reading:
E 6 4 E B 1 3 O
An Even Parity Bit of 6 4 E = 0 An Odd Parity Bit of B 1 3 = 1
c) The 26 bits Wiegand Data Sending Out in Hex Binary from Reading The Card:
0 0 1 1 0 0 1 0 0 1 1 1 0 1 0 1 1 0 0 0 1 0 0 1 1 1
d) The Arrangement of The Site Code and ID Number of A 26-bit EM Card:
● Site Code: Bit 2 ~ 9 (000~255)
● ID Number: Bit 10 ~ 25 (00000 ~ 65,535)