Printronix T4204 - Manual (Page 183)

Terminating Resistor Configurations
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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. These 470
ohm pull-up and 1K ohm pull-down terminating resistors are located at RP2
and RP1 on the Controller PCBA.
If the values of these terminating resistors are not compatible with the
particular interface driver requirements of your host computer, you may need
to install resistors with different pull-up and pull-down values.
Figure 6. Resistor Locations
The shipping kit for this printer includes 220 ohm pull-up and 330 ohm pull-
down alternate terminating resistors. If you install the 220 ohm pull-up
resistor, you must also install the 330 ohm pull-down resistor.
RP1
RP2