Serial Interface - Epson DFX-9000 Service Manual

Epson DFX-9000

1.2.8.3 Serial interface

Synchronization: Asynchronous
Signal level: EIA-232D
MARK logical 1: –3 V to –25 V
SPACE logical 0: +3 V to +25 V
Word length:
Start bit: 1 bit
Data bit: 8 bit, 7 bit
Parity bit: Odd, Even, None, Ignore
Stop bit: 1 bit or more
Baud rate: 300, 600, 1200, 2400, 4800, 9600 or 19200 BPS
Handshaking: DTR signal and XON/XOFF
DTR = MARK, XOFF: indicates that the printer
cannot receive data.
DTR = SPACE, XON: indicates that the printer is
ready to receive data.
NOTE: The DTR signal is MARK, and the XOFF code (DC3, 13h) is
transmitted when the remaining space in the input buffer is
256 bytes. The DTR signal is SPACE, and the XON code
(DC1, 11h) is transmitted as soon as the available space in
the input buffer exceeds 256 bytes.
Error handling: Only parity errors are detected. Overrun and
framing errors are ignored.
Connector: 25-pin subminiature D-shell connector (female)
Product Description
Table 1-22. Connector pin assignment
Pin
Signal name
No.
2 TXD
20 DTR
11 REV
4 RTS
3 RXD
7 Signal GND
1 Chassis
GND
Other NC
* In/Out refers to the signal flow direction from the printer's point of
view.
Basic specifications
In/
Function description
*
Out
Out Transmits data.
Out Indicates whether the printer is ready to
receive data or not.
Out Connected directly to the DTR signal.
Out Requests to send. Always SPACE level
when the printer is powered on. Pulled
up to +12 V via 4.7 kΩ resistor.
In Receives data.
- Signal GND.
- Chassis GND.
- Not used. Not connected.
Revision B
29