Epson SQ-2550, SQ-850 Serial interface, Technical Specifications, Data format, Printing enabledldisabled signals and control conditions

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	High	DC1	**	High	High/Low	Pulsed		Enabled
		Recv’d				ea. char.
on line	High	DC3	**	High	High/Low	Pulsed		Disabled*
		Recv’d				ea. char.
off line	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	lbit
Start bit:
Data word length:	8 bit
Parity bit:	Odd, even or no parity
Stop bit:	1 bit or more
Baud rate	300, 600, 1200, 2400, 4800, 9600, 19200
	bits per second.

Technical Specifications 8-13