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and
more
about Sharp
PC-1
500 at
http://www.PC-1500.info
Serial signal
Transmit and receive
data
are handled
in
a form of serial signal as
illustrated
below.
(Waveform
as observed at the
1/0
pin of the
DB··
2 5W.I
Absence of data
must
be stop bits.
LSB
(M
SB
l
~~·
.......
,
......
.,.
...... ·.-....
...... -.... -'
-.. -. -..
.
.
---.
-..•..
--.
-"p"
... .
Stop bit
Start: Data
:
:
:
:
:
:
:
:
anty
----~
bit
:
..
'?!!
..
·.
~
.. ·--·-·'·-·
-·. --
~
----. -.
:
.......
i ........
;
...
·-·
.. : ...
·-...
:.
' ?!!
..
.
a
1
2
3
4
(SJ
(6)
(7)
Stop
:s1op
Next:
..
.
bit
;bit
start
\
..
3
(1)
bit
Data bits. 5. 6, 7. parity
bit,
and stop bit
1
may not exist,
depending on the
communication
parameter used.
(11
Transmission
speed
(baud
rate)
Represcnts
·number of
bits tran.sl')>itted
per
second
,
including the
start
bit, data
bit, parity
bit.
and stop bit.
(21 Character
length
Represents
number
of
bits used to
comprise a single transmission
characte
r.
(3)
Parity
bit
A bit
attached
next to the Ian data bit (MSB). Three modes of non-parity,
even parity,
and odd parity can
be
chosen to check data accuracy.
{4)
Stop bit(s)
Bit(s) attached next to ·the data bit or
parity
bit;
the
size varies from
1to1.5,
and 2.
Interfacing signal
Signal
levels at
the
1/0 pins of
the
DB-25W connector
shall
be
as
follows:
Input
signal
High
level
(SP
ACE or ON
s~ate
of
signal)
: +(3
to
15)
V
Low level {MARK or OFF
state of
siqnal):
-(3
to
15)
V
Output signal
High level
:
+{5 to 10) V
Low level:
-
15
to 10) V
As
lhe
level
of
the
output signal
i·
s measured with the
load
of
3
to
7
Kohms
with the
cable
length of
1
meter.
Please note that
there may
be
a case when the above
condiiion
is
not
met.
if
the
load is out
of
above
range
or the
cable
length
is longer,
or
the
cable capacity
is larger.
10
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sell
this
PDF
!!!
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