Epson T70 Functions of each connector pin, Pin no Signal name Signal direction Function

Functions of each connector pin

Pin no.	Signal name	Signal direction	Function
1	FG	—	Frame ground
2	TXD	Output	Transmission data
3	RXD	Input	Reception data
4	RTS	Output	Equivalent to DTR signal (pin 20)
6	DSR	Input	This signal indicates whether the host computer can
			receive data.
			SPACE indicates that the host computer can receive
			data. MARK indicates that the host computer
			cannot receive data.
			When DTR/DSR control is selected, the printer
			transmits data after confirming this signal (except if
			transmitted using some ESC/POS commands).
			When XON/XOFF control is selected, the printer does
			not check this signal.
			Changing DIP switch 2-7 lets this signal be used as a
			printer reset signal.
			When you use this signal as the printer’s reset signal,
			the printer is reset when the signal remains MARK for
			a pulse width of 1 ms or more.
7	SG	—	Signal ground
20	DTR	Output	1) When DTR/DSR control is selected, this signal
			indicates whether the printer is BUSY.
			• SPACE status
			Indicates that the printer is ready to receive data.
			• MARK status
			Indicates that the printer is BUSY. Set BUSY conditions
			with DIP switch 2-1.
			2) When XON/XOFF control is selected, the signal
			indicates that the printer is properly connected and
			ready to receive data from the host. The signal is
			always SPACE, except in the following cases:
			• During the period from when power is turned on to
			when the printer is ready to receive data.
			• During the self-test.
25	INT	Input	Changing DIP switch 2-8 enables this signal to be
			used as a reset signal for the printer. The printer is
			reset if the signal remains at SPACE for a pulse width
			of 1 ms or more.

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