Serial Interface - Epson LX-300+ Service Manual

LX-300+/1170
Table 1-13. Connector Pin Assignment and Signals (Reverse Channel)
Return
Pin No. Signal Name GND
Pin
17 Chassis --
16, 33,
GND --
19-30
15, 34 NC --

1.3.3 Serial Interface

o
Synchronization: Asynchronous
o
Signal level: EIA-232D
MARK (logical 1):
SPACE (logical 0):
o
Word length: Start bit:
Data bit:
Data bit:
Parity bit:
Stop bit:
o
Baud rate: 300, 600, 1200, 2400, 4800, 9600 or 19200 bps
o
Handshaking: DTR signal and XON/XOFF
DTR=MAEK, XOFF:indicates that the printer cannot
DTR=MARK, 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.
o
Error handling: Parity error is only detected. Overrun error and
framing error are ignored.
o
Connector: 25 pin subminiature D-shell connector (female)
PRODUCT DESCRIPTION
In/Out Functional Description
-- Chassis GND.
Signal GND.
--
-- Not connected.
-3V to -25V
+3V to +25V
1 bit
8 bit (LX-300+ only)
8 bit, 7 bit (LX-300+/1170)
Odd, Even, Non, Ignore
1 bit or more
receive data.
to receive data.
Table 1-14. Connector Pin Assignment and Signals
Pin
Signal Name
No.
2 TXD
20 DTR
11 REV
4 RTS
3 RXD
7 Signal GND
1 Chassis GND
other NC
* In/Out shows the direction of signal flow from the printer's point of view.
Interface Specifications
In/Out Functional Description
Out Transmit data.
Out Indicates that the printer is ready to receive data or not.
Out Connected directly to the DTR signal.
Request to send. Always SPACE level when the printer
Out
is powered on. Pulled up to +12V via 4.7KΩ resistor.
In Receive data.
-- Signal GND
-- Chassis GND
-- Not used. Not connected.
Revision C
24