Transmission Code And Bit Order; Vertical Parity - Denso BHT-1505B User Manual

BHT-1500B Series
 Transmission Code and Bit Order
• All characters should be coded to 7 or 8-bit code for data transmission.
• The standard code at the BHT is ASCII 7-bit or 8-bit code.
• The transmission bit order is LSB (Least significant bit) first.
The example below is for the transmission of an ASCII 8-bit code A (41h or 01000001b, b: binary) with
even vertical parity and a single bit each for the start and stop bits.
Start bit
 Vertical Parity
A vertical parity bit is a redundant bit that is added to every character transmitted in order to check that
data has been transmitted accurately. The parity bit should be set to either "1" or "0" depending upon the
parity parameter setting to make the number of set bits in the character even or odd. The receiver counts
the number of set bits in the transmitted character code to make sure that it has the specified number
(even or odd) of set bits.
The vertical parity bit is positioned immediately after the MSB (Most significant bit) as shown below.
192
7 bit data
8 bit data
Stop bit
Parity bit
Vertical parity bit
Vertical parity bit