Serial Interface - Epson DLQ-3000 Service Manual

1.4.2 Serial Interface

Y
Synchronization
Y
Signal level
Y
Word format
Y
Baud rate
Y
Handshaking
DTR = MARK, XOFF:
DTR = SPACE, XON:
The DTR signal is MARK and XOFF code (DC3, 13H) is transmitted when the rest of
the input buffer becomes 256 byte. The DTR signal is SPACE and XON code (DC1,
11H) is transmitted when the rest of the input buffer becomes 256 byte.
Y
Error handling
Y
Connector
Table 1-27. Connector Pin Assignment for Serial Interface
Pin No. Signal Name
1 Chassis GND
2 TXD
3 RXD
4 RTS
7 Signal GND
11 REV
20 DTR
others
Note: In and Out refers to the direction of the signal flow from the printer's point of
view.
Rev. A
Asynchronous
EIA-232D
MARK (logical 1):
SPACE (logical):
Start bit:
Data bit:
Parity bit: Odd, Even or Non
Stop bit:
300, 600, 1200, 2400, 4800, 9600 or 19200 bps
DTR signal and XON/XOFF
Indicates that the printer is ready to receive data.
Parity error is detected only.
(Overrun error and framing error are ignored.)
25-pin sub-miniature D-shell connector. (female)
I/O
Out
In
Out
Out
Out
NC
1 bit
8 bit
1 bit
Indicates that the printer cannot receive data.
Function Description
Chassis GND
Transmits data
Receives data
Request to send. Always SPACE level
when the printer is powered on. Pulled
up to +12 V via 4.7 L ohm resistor.
Signal GND
Connected directly to the DTR signal.
Data terminal ready
Not used. Not connected.
Product Description
-3 V to -25 V
+3 V to +25 V
1-33