Serial Interface Specifications - Epson DLQ-3000 Service Manual

Product Description

1.3.2 Serial Interface Specifications

Data format:
Synchronization:
Handshaking
Table 1-12. Serial Interface Handshaking
I
Protocol
MARK X-OFF (DC3/13H)
SPACE X-ON (DC1/1 IH)
S P A C E
8K byte
Figure 1-6. Handshaking for RS-232C Interface
Word length
Start bit:
Data bit:
Parity bit:
Stop bit:
Bit rate:
Logic level:
Error handling:
Connector:
Asynchronous
By DTR (REV) signal or X-ON/OFF protocol
When the number of bytes remaining in the input buffer
reaches 256 or less, the signal level goes to MARK and
X-OFF code is sent to the host computer. This indicates
that the printer is not ready to receive data.
When the number of bytes remaining in the input buffer
reaches 512 or less, the signal level goes to SPACE and
X-ON code is sent to the host computer. This indicates that
the printer is ready to receive data.
512 byte 256, byte
X - O N X - O F F
1 bit
8 bits
Odd, Even, or None
1 bit or more
300, 6(X), 1200, 24(XI, 4800,9600,19,200 bps
MARK (logical 1): -3V to -25V
SPACE (logical 1): +3V to +25V
When parity error is detected, the received byte is changed to the
"*" character cede. Overrun error and framing error are ignored.
25 pin subminiature D-shell comector (female) or equivalent
Description
Buffer Vacant Area
X-ON/X-OFF Protocol