Terminating Resistor Configurations - Printronix SL5000r User Manual

Chapter 5
IEEE 1284 Parallel Interface
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.
nReverse Request. Driven by the host. Resets the interface and forces a
return to Compatibility Mode idle phase.
nData Available / nPeripheral Request. Driven by the printer. Indicates the
printer has encountered an error. (Data bits 1 and 5 in Nibble Mode.)
1284 Active / nAStrobe. Driven by the host. A peripheral device is selected.
Host Logic High. Driven by the host. When set to high, the host indicates all
of its signals are in a valid state. When set to low, the host indicates its power
is off or its signals are in an invalid state.
nInit. Resets init interface from the host.

Terminating Resistor Configurations

The factory equips the printer with terminating resistors that are used for
parallel interface configurations suitable for most applications. The 1K ohm
pull-down resistor pack is located at RP1 and the 470 ohm pull-up resistor
pack is located at RP2 on the Controller PCBA.
If the values of these terminating resistors are not compatible with the
particular interface driver requirements of your host computer, call your printer
service representative.
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