Printronix T4204 manual Centronics Parallel Interface Signals

Centronics Parallel Interface Signals

Centronics Parallel Interface Signals

Table 8. Centronics Parallel Interface Signals

Signals	Purpose
Data Lines 1 through 8	Provide eight standard or inverted levels from
	the host that specify character data, plot data,
	or a control code. Data Line 8 allows access to
	the extended ASCII character set. You may
	enable or disable this line via the Data Bit 8
	parameter on the Centronics Parallel submenu
	(see page 80).
Data Strobe	Carries a low true, 100 ns minimum pulse from
	the host that clocks data into the printer.
Acknowledge	A low true pulse from the printer indicating the
	character or function code has been received
	and the printer is ready for the next data
	transfer.
Online	A high true level from the printer to indicate the
	printer is ready for data transfer and the PAUSE
	key on the control panel has been activated.
	When the printer is in online mode, it may
	accept data from the host.
Paper Empty (PE)	A high true level from the printer to indicate the
	printer is in a paper empty or paper jam fault.
Busy	A high true level from the printer to indicate the
	printer cannot receive data.
Prime	A high true level from the host to indicate the
	printer should perform a warm start (printer is
	reset to the power-up configuration values).
Paper Instruction (PI)	Carries a VFU signal from the host with the
	same timing and polarity as the data line.
Fault	A low true level from the printer indicates a
	printer fault.

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