Citizen Systems iDP-460 - Handbuch (Seite 37)

iDP-460 User’s Manual
37 CITIZEN
7.3.2 Data Configuration
t
Mark
b
0
, b
1
, b
2
, ••••
Space (1) (2) (3)
(1) Start Bit
(2) Data Bit (+ Parity Bit)
(3) Stop Bit (1 or More)
(1) Start bit
After a lapse of 1/2 bit from a mark-to-space fall edge, the state is read again, and if it is a
space, it is recognized as the start bit. If it is a mark, it is assumed neither the start bit
nor an error, and it is attempted to detect the start bit again.
(2) Data bit + parity bit
The data bit and parity bit are sampled for 1 bit worth of time from the 1/2 start bit. The
then state is assumed the data for the corresponding bit. A sequence of the bits are
named Bit 0, Bit 1, ..., parity bit, starting from the one closest to the start bit.
(3) Stop bit
The stop bit is a mark level of 1 bit or more. If a space is detected in detecting the stop bit,
a framing error results.