Bcc For Horizontal Parity Checking - Denso BHT-4000 User Manual

3.3.6 BCC for Horizontal Parity Checking

To check that data has been transmitted accurately, the BHT-4000 supports horizontal
parity checking for every transmission block.
In horizontal parity checking, a horizontal parity byte so called BCC (Block Check
Character) is suffixed to an ETX of every transmission block.
In the BHT-protocol, every parity bit of BCC is set so that all set bits at the same bit
level (including a parity bit) in the characters contained in the transmission block have
an even number by binary addition, except for SOH, STX, and functions SOH$ and
STX$.
(For details about SOH$ and STX$ which are protocol functions unique to BHT-BASIC
3.0, refer to the "BHT-BASIC 3.0 Programmer's Manual.")
(Vertical parity)
Shown below is a data text block in Easy Pack 4.2 indicating the bits to be added for
horizontal parity checking.
b7
b0
Character
[ For 8-bit data ]
S
Serial
T
number
X
To be added for
horizontal parity
checking
Horizontal parity byte
(BCC)
E
Data text
T
X
94
B
C
C