Serial Interface - Epson LX-300+II RTP Service Manual

EPSON LX-300+II/300+II RTP/1170II

1.3.3 Serial Interface


Synchronization: Asynchronous

Signal level: EIA-232D
MARK (logical 1):
SPACE (logical 0):

Word length: Start bit:
Data bit:
Parity bit:
Stop bit:
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Baud rate: 300, 600, 1200, 2400, 4800, 9600 or 19200 bps

Handshaking: DTR signal and XON/XOFF
DTR=MAEK, XOFF:indicates that the printer cannot
DTR=SPACE, XON: indicates that the printer is ready
NOTE: The DTR signal is MARK and XOFF code (DC3, 13H) is transmitted
when the rest of the input buffer becomes 256 bytes. The DTR signal is
SPACE and XON code (DC1, 11H) is transmitted when the rest of the
input buffer is regained 256 byte.

Error handling: Parity error is only detected. Overrun error and framing
error are ignored.

Connector: 25 pin subminiature D-shell connector (female)
PRODUCT DESCRIPTION
-3V to -25V
+3V to +25V
1 bit
8 bits, 7 bits
Odd, Even, Non, Ignore
1 bit or more
receive data.
to receive data.
Interface Specifications
Table 1-18. Connector Pin Assignment and Signals
Pin
Signal Name In/Out
No.
2 TXD Out Transmit data.
20 DTR Out Indicates that the printer is ready to receive data or not.
11 REV Out Connected directly to the DTR signal.
Request to send. Always SPACE level when the printer
4 RTS Out
is powered on. Pulled up to +12V via 4.7KΩ resistor.
3 RXD In Receive data.
7 Signal GND -- Signal GND
1 Chassis GND -- Chassis GND
other NC -- Not used. Not connected.
NOTE: In/Out shows the direction of signal flow as viewed from the printer.
Revision D
Functional Description
21