Справочник Пользователя для Denso BHT-100B
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[ 3 ] BCC for Horizontal Parity Checking
To check whether data has been transmitted accurately, the BHT supports horizontal
parity checking for every transmission block.
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.
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, excluding SOH, STX, and functions SOH$ and
STX$.
level (including a parity bit) in the characters contained in the transmission block have
an even number by binary addition, excluding SOH, STX, and functions SOH$ and
STX$.
(For details about SOH$ and STX$ which are protocol functions unique to BHT-BASIC,
refer to the "BHT-BASIC Programmer's Manual (BHT-100 series).")
refer to the "BHT-BASIC Programmer's Manual (BHT-100 series).")
Character
(Vertical parity)
Horizontal parity byte
(BCC)
[ For 8-bit data ]
Shown below is a data text block indicating the bits to be added for horizontal parity
checking.
checking.
To be added for
horizontal parity
checking
horizontal parity
checking
Serial
number
number
Data text
b7
b0