Printronix SL_T5R Energy Star User Manual

Page 286

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Chapter

IEEE 1284 Parallel Interface

NOTE:

The length of the data cable from the host computer to the printer
should not exceed 32 feet (10 meters).

Host Clock / nWrite.

Driven by the host. Data is transferred from the host to

the printer. When the printer sends data, two types are available. If it is Nibble
Mode, the signal is set high. If it is Byte Mode, the signal is set low.

Data 1 through Data 8.

These pins are host-driven in Compatibility Mode and

bidirectional in Byte Mode. They are not used in Nibble Mode. Data 1 is the
least significant bit; Data 8 is the most significant bit.

Printer Clock / Peripheral Clock / Interrupt.

Driven by the printer. A signal

from the printer indicating the character or function code has been received
and the printer is ready for the next data transfer.

Printer Busy / Peripheral Acknowledge / nWait.

Driven by the printer.

Indicates the printer cannot receive data. (Data bits 4 and 8 in Nibble Mode.)

Acknowledge Data Request / nAcknowledge Reverse.

Driven by the

printer. Indicates the printer is in a fault condition. (Data bits 3 and 7 in Nibble
Mode.)

Xflag.

Driven by the printer. A high true level indicating the printer is ready for

data transfer and the printer is online. (Data bits 2 and 6 in Nibble Mode.)

Host Busy / Host Acknowledge / NDStrobe.

Driven by the host. Activates

auto-line feed mode.

Peripheral Logic High.

Driven by the printer. When the line is high, the

printer indicates all of its signals are in a valid state. When the line is low, the
printer indicates its power is off or its signals are in an invalid state.

Signal Ground (Data 7)

Signal Ground (Data 8)

Signal Ground (PError, Select, nAck)

Signal Ground (Busy, nFault)

Signal Ground (nAutoFd, nSelectIn, nInit)

Host

nInit

Printer

NFault

nDataAvail

aDataAvail

Not Defined

Host

nSelectIn

1284 Active

Table 14. IEEE 1284 Signals (continued)

Pin

Source of Data

Type of Mode

Compatible

Nibble

Byte