B
‐
FV700
‐
BLTH
‐
QM
‐
R
‐
46
‐
6.6.3 RS‐232C
The
RS
‐
232C
on
the
printer
is
DB9
female.
It
transmits
data
bit
by
bit
in
asynchronous
start
‐
stop
mode.
The
figure
below
shows
its
pinout.
1
2
3
4
5
6
7
8
9
Pin
Signal
Description
1
N/A
Shorted
to
Pin
6
2
RxD
Receive
3
TxD
Transmit
4
N/A
No
Connection
5
GND
Ground
6
N/A
Shorted
to
Pin
1
7
RTS
Request
to
Send
8
CTS
Clear
to
Send
9
+5V
Reserved
for
KDU
(keyboard
device
unit)
Note
Pin
9
is
reserved
for
KDU.
Do
not
connect
it
if
you
are
using
a
computer
as
the
host.
Host
(DB9)
Printer
(DB9)
Signal
Description
Pin
Pin
Description
Signal
RxD
Receive
2
3
Transmit
TxD
TxD
Transmit
3
2
Receive
RxD
DTR
Data
Terminal
Ready
4
1
Data
Set
Ready
DSR
GND
Ground
5
5
Ground
GND
DSR
Data
Set
Ready
6
6
Data
Terminal
Ready
DTR
RTS
Request
to
Send
7
8
Clear
to
Send
CTS
CTS
Clear
to
Send
8
7
Request
to
Send
RTS
6.6.4 Centronics
The
36
‐
pin
Centronics
on
the
printer
uses
parallel
communication,
and
complies
with
IEEE
1284
compatibility
mode
(also
called
SPP,
Standard
Parallel
Port).
The
figure
below
shows
its
pinout.