Communications specifications, Serial port connections, Dsr/dtr handshaking – Rice Lake EPSON TM-U590 User Manual
Page 2: Xon/xoff handshaking, Sample serial connection
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25
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Serial Port Connector
This document provides communications interface information not included
in the manuals supplied with the TM-295 Ticket Printer, TM-U200 Tape Printer
and TM-590 Ticket Printer. Please keep this information with the manual for
your printer.
Communications Specifications
Data transmission: Serial (RS-232C–compatible)
Synchronization:
Asynchronous
Handshaking:
DTR/DSR or XON/XOFF control
Signal level:
MARK (–3 to –15V, logical “1”)
SPACE (+3 to +15V, logical “0”)
Baud rates:
TM-295: 1200, 2400, 4800, 9600 bps
TM-U200: 4800 or 9600 bps
TM-U590: 2400, 4800, 9600, 19200
Data length:
7 or 8 bits
Parity:
None, even, or odd
Stop bits:
1 or more
Serial connector:
D-SUB25 female connector or equivalent
Serial Port Connections
The following figure shows the pin numbering scheme for the serial port:
Pin assignments for the serial port connector are as follows:
r
e
b
m
u
N
n
i
P
l
a
n
g
i
S
n
o
i
t
c
n
u
F
1
G
F
d
n
u
o
r
g
e
m
a
r
F
2
D
x
T
a
t
a
d
t
i
m
s
n
a
r
T
3
D
x
R
a
t
a
d
e
v
i
e
c
e
R
6
R
S
D
y
d
a
e
r
t
e
s
a
t
a
D
7
G
S
d
n
u
o
r
g
l
a
n
g
i
S
0
2
R
T
D
y
d
a
e
r
l
a
n
i
m
r
e
t
a
t
a
D
DSR/DTR Handshaking
The DSR/DTR handshaking uses pins 6 and 20 to signal availability of the printer
and host computer to receive data:
DSR (pin 6) indicates whether the HOST COMPUTER is ready to receive data:
SPACE (logical 0): Host computer is ready to receive data
MARK (logical 1): Host computer is
not ready to receive data
DTR (pin 20) indicates whether the PRINTER is ready to receive data:
SPACE (logical 0): Printer is ready to receive data
MARK (logical 1): Printer is
not ready to receive data
DTR is set to MARK (logical 1) during power-up, self-test, and error states, or
when the receive buffer is full.
NOTE: DSR/DTR handshaking cannot be used if pin 6 is used as a reset signal input.
XON/XOFF Handshaking
When XON/XOFF handshaking is selected, the printer transmits XON/XOFF
characters as follows:
XON (
<11>
H
) is sent whenever the printer goes online or when the receive buffer is
released from the buffer-full state.
XOFF (
<13>
H
) is sent whenever the printer goes offline, the receive buffer is full, or
when an error state exists.
XON/XOFF handshaking ignores DSR input signals (pin 6). The DTR output (pin
20) is always held to SPACE (logical 0) except during power-up, self-test, and error
states.
Sample Serial Connection
The following figure shows an example of connections made between a host
computer (configured as the DTE) and a printer.
TXD
RXD
DSR
CTS
DTR
Host
Computer
Printer
3
2
6
20
TXD
RXD
DSR
DTR
SG
7
SG
© 2002 Rice Lake Weighing Systems, Inc., Rice Lake, WI USA. All Rights Reserved
Rice Lake Weighing Systems, Inc. 230 West Coleman Street, Rice Lake, WI 54868
12/02