Stid ultrys - Clock & Data 2 B

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© STid – MU_ULTRYS_V3.0.1_EN
Clock & Data 2B
Reading an ID of 5 bytes (40 bit) and convert to decimal.
Message
The frame consists of a first series of 16 synchronization zeros followed by 5-bit characters (4 bits,
LSB first, plus 1 parity bit). It ends with 1 trailing zero without a clock.
The message consists of the following:
Start Sentinel: 1character 1011b (0x0B) – parity bit 0. Transmission 1101 0
Data: According to the protocol: 13 or 10 decimal characters
End Sentinel: 1character 1111b (0x0F) - parity bit 1. Transmission 1111 1
LRC: 1 control character, which is the « XOR » of all characters of all
characters sent from "Start Sentinel" to "End Sentinel".
Trailing zero: The "Data" signal encodes a "0" until "Code" returns to its normal
position.
During this time, there is no activity of the "Clock" signal.
Example
For a hexadecimal user code of “0x187E775A7F”, the output code will be: “0105200966271”.
Frame sent by reader will be:
000...
1101 0
0000 1
1000 0
0000 1
1010 1
0110 1
0100 0
1110 0
1000 0
1111 1
1111 1
0000
B
0
1
0
5
2
009
6
6
2
7
1
F
F
16 Zeros
S.S
Char.1
Char.2
Char.3
Char.4
Char….
Char.10
Char.11
Char.12
Char.13
E.S
LRC
Zero
VARIANT
Decoding
Data
Values
2B
Decimal (BCD)
13 characters
0 to 9
16 leading zeros
Start Sentinel
Data
End Sentinel
LRC
1 trailing zero