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10. 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
D0
D1
Data bit 0 = approximately 100 us (microseconds)
Data bit 1 = approximately 100 us (microseconds)
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:
Parity bit (bit 1) + 8 bits header
P1
XXXXXXXX
Example:
170
1
1 0 1 0 1 0 1 0
Note: Parity bits are calculated as follows:
P1 = even parity calculated over the bits 2 to 13 (X)
E A A A A A A A A B B B B B B B B B B B B B B B B O
11. Safety Precautions
• Do not install the device in a place subject to direct sun
light without protective cover.
• Do not install the device and cabling close to a source
of strong electro-magnetic fields like radio-transmitting
antenna.
• Do not place the device near or above heating
equipments.
0
0
5V
0V
1 ms
100 us
5V
0V
+
16 bits user code = 2 bytes
XXXXYYYY YYYYYYYY
0 1 1 1 1 0 1 1 0 0 1 0 0 1 1 1
P2 = odd parity calculated over the bits 14 to 25 (Y)
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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....
1
Time between two data bits: approximately 1 ms
(millisecond). Both data lines (D0 and D1) are high.
+
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• If cleaning, do not spray or splash water or other
cleaning liquids but wipe it out with smooth cloth
or towel.
• Do not let children touch the device without supervision
Note: that if the sensor is cleaned by detergent, benzene
or thinner, the surface will be damaged and the fingerprint
can't be entered.
CV-940 Series
0
Parity bit (bit 26)
P2
0
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