Printronix T4204 - Manual (Page 179)

Centronics Parallel Interface Signals
179
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.