Epson T-750 BUSY, ERROR, ACKNLG, On-Line, DC1/DC3, Printing, on), SLCT IN, (Indicator, (Disabled/enabled)

Table E-2. Printing enabled/disabled signals and control conditions

On-Line			DC1/DC3				Printing
		SLCT IN		ERROR	BUSY	ACKNLG
(Indicator	on)		(Data on/off contr.)				(Disabled/enabled)
ON-LINE		LOW	DC1 /DC3	HIGH	HIGH/LOW	PULSED EA. CHAR.	ENABLED
		(interface)	(no effect)				(normal cond.)
ON-LINE		HIGH	DC1 RECV’D	HIGH	HIGH/LOW	PULSED EA. CHAR.	ENABLED
ON-LINE		HIGH	DC3 RECV’D	HIGH	HIGH/LOW	PULSED EA. CHAR.	*DISABLED
OFF-LINE		HIGH/LOW	DC1 /DC3	LOW	HIGH	NOT GENERATED	DISABLED
		(no effect)	(no effect)

‘Even though printing is disabled, data characters are received and acknowledged, since the printer is looking for another DC1 character, which would allow it to resume printing.