Serial Interface; Data Format; Parity Bit - Epson SQ-2550 User Manual

Printing enabledldisabled signals and control conditions
The table below shows the relationship between printing being
enabled or disabled, the on line/off line status, the printer
select signal (SLCT IN), and the receipt of data on/off control
characters, DC1 /DC3.
ON LINE
SLCT IN DCl/DC3 ERROR
(Indicator
on)
Low
on line
on line High
on line High
off line High/Low DCl/DC3 Low
(no effect) (no effect)
* While printing is disabled, data characters are received and
acknowledged so that the printer can look for another DC1
character, which allows it to resume printing.
** Enable only when the SelecType DCl/DC3 setting is On.

Serial interface

The built-in serial interface is an RS-232C asynchronous
interface with the following characteristics:

Data format

Start bit:
Data word length:

Parity bit:

Stop bit:
Baud rate
(Data
on/off
control)
DCl/DC3 High
(no effect)
** High
DC1
Recv'd
** High
DC3
Recv'd
lbit
8 bit
Odd, even or no parity
1 bit or more
300, 600, 1200, 2400, 4800, 9600, 19200
bits per second.
BUSY ACKNLG Printing
High/Low Pulsed
ea. char.
High/Low Pulsed
ea. char.
High/Low Pulsed
ea. char.
High Not
generated
Technical Specifications 8-13
(Disabled,
enabled)
Enabled
(normal
cond.)
Enabled
Disabled*
Disabled