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NETRONIX
5.4. Wiegand protocol
The format conforms WIEGAND protocol specification for N bits. During operation,
a module tries to read-out transponder periodically. If it fails (no successful read-out),
module does not send data (bus does not "see" the module). If module reads out the
transponder, the module starts to send data via Wiegand bus.
Pulse sequence from left to right.
H level
L level
H level
L level
1
1
Total number of pulses (level L) is equal to N. The first being bit sent complements up
to parity the bits from first half of total bits. The last bit N complements up to non-parity
the bits from second half of bits being sent.
It means, that two bits out of N bits assure the transmission correctness. Information is
being sent is written by means bits 2 to N-1, it gives N information bits.
Check sums for bit sequence:
for even N:
EXXXXXXXXXXXXYYYYYYYYYYYYO
or for odd N:
EXXXXXXXXXXXXXXXXXX..................
..................YYYYYYYYYYYYYYYYYYO
Where:
E = bit complementing up to parity
O = bit complementing up to non-parity
X = mask for parity calculation
Y = mask for non-parity calculation
NETRONIX
......
......
0
0
1
.............
DATA1
DATA0
1
0
0
encoding DATA
CTU-Mxx
.
12
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