Symbol PDT 1100, Product Reference Manual

Page: 103 / 124

A-7
Specifications
Figure A-3. Vertical Parity
BCC for Horizontal Parity Checking
The PDT 1100 supports horizontal parity checking for every transmission block to check
data transmission. A horizontal parity byte called BCC (Block Check Character) is
appended after the ETX of every transmission block. Every parity bit of BCC is set so that
all set bits at the same bit level (including a parity bit) in the transmission block characters
have an even number by binary addition, excluding SOH, STX, and functions SOH$ and
STX$. (For details about SOH$ and STX$ protocol functions which are unique to BASIC
3.0 interpreter, refer to the PDT 1100 Terminal Programmer’s Guide, p/n 70-36099-xx.)
Figure A-4. Horizontal Parity Checking
MSB LSB
b0 b1 b2 b3 b4 b5 b6
Vertical Parity Bit
Vertical Parity Bit
MSB
LSB
b0 b1 b2 b3 b4 b5 b6 b7
(Vertical Parity)
Character Horizontal Parity Byte
(BCC)
[For 8-bit Data]
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