Functionality
16 AY-x55 Family Installation and Programming Manual
More information on each of the different keypad transmission
formats is available on the following pages.
Option 1: Single Key, Wiegand 6-Bit (Rosslare Format)
Each key press immediately sends 4 bits with 2 parity bits added –
even parity for the first 3 bits and odd parity for the last 3 bits.
0 = 1 1010 0 ="A" in Hexadecimal 6 = 1 0110 0
1 = 0 0001 0 7 = 1 0111 1
2 = 0 0010 0 8 = 1 1000 1
3 = 0 0011 1 9 = 1 1001 0
4 = 1 0100 1
= 1 1011 1 ="B" in Hexadecimal
5 = 1 0101 0 # = 0 1100 1 ="C" in Hexadecimal
Option 2: Single Key, Wiegand 6-Bit Nibble and Parities
Each key press immediately sends 4 bits with 2 parity bits added –
even parity for the first 3 bits and odd parity for the last 3 bits.
0 = 0 0000 1 6 = 1 0110 0
1 = 0 0001 0 7 = 1 0111 1
2 = 0 0010 0 8 = 1 1000 1
3 = 0 0011 1 9 = 1 1001 0
4 = 1 0100 1 = 1 1010 0 = "A" in Hexadecimal
5 = 1 0101 0 # = 1 1011 1 = "B" in Hexadecimal
Option 3: Single Key, Wiegand 8-Bit Nibbles
Complemented
This option inverts the most significant bits in the message leaving the
least 4 significant bits as a Binary Coded Decimal (BCD) representation
of the key. The host system receives an 8-bit message.