Epson SQ-2550, SQ-850 manual 236

ecomes LOW, the

				printer controller is reset to its
				power-up state and the print buffer is
				cleared. This level is usually HIGH;
				its pulse width must be more than 50
				microseconds at the receiving
				terminal.
			OUT	This level becomes LOW when the
32		ERROR
				printer is:
				1) in paper out state.
				2) off line.
				3) in error state.
33	-	GND		Same as for Pins 19-30.
34		NC		Unused.
35			OUT	Pulled up to +5V through 3.3K ohm
				resistance.
36			IN	The DCl/DCS code is valid only
		SLCT IN
				when this signal is HIGH. (The same
				effect can be achieved by setting
				SelecType.)

Technical Specifications 8-11