Epson SQ-2550, User Manual

Page: 238 / 315

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