Epson EPL-5500, Service Manual

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1.3.3 Optional LocalTalk Interface
This printer can use the optional LocalTalk/ serial interface module.
Type:
LocalTalk
Signal level: Same as RS-422 signal level
Protocol: X-ON/X-OFF (cannot be combined with DTR control)
DTR control (cannot be combined with X-ON/X-OFF)
Transfer speed: 230.4K bps
Signal description: See Table 1-11.
Table 1-11. LocalTalk Interface Pin Assignments
Pin No. Signal Name I/O Description
1
DTR
OUT
Signal output by the printer. When the DTR signal is HIGH, the
printer can receive the RXD signal.
2
CTS
IN
The printer transmits the data through TXD while CTS is HIGH.
3
TXD-
OUT
Serial ASCII data output from the printer.
HIGH level; when SD+ voltage is higher than the SD- voltage.
LOW level; when SD+ voltage is less than the SD- voltage.
Logic 0 is SPACE and logic 1 is MARK. The state must be
maintained between transmitted character codes.
4
GND
—
Ground.
5
RXD-
IN
Serial ASCII data input from computer.
HIGH level; when RD+ voltage is higher than RD- voltage.
LOW level; when RD+ voltage is less than RD- voltage.
Logic 0 is “SPACE” and logic 1 is “MARK” state must be
maintained between transmitted character codes.
6
TXD+
OUT
Refer to TXD-.
7
NC
—
No connect.
8
RXD+
IN
Refer to RXD-.
EPL-5500 Service Manual General Description
Rev. B 1-17