Terminating Resistor Configurations - IBM 6500 User Manual

Terminating Resistor Configurations

The factory equips the printer with several resistors that are used for parallel
interface configurations and are suitable for most applications. These 470 ohm
pull-up and 1K ohm pull-down terminating resistors are located at RP1 and RP2,
shown in Figure 13.
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.
Note: Must be installed by an IBM service representative.
Figure 13. 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. Table 9 lists the three terminating
resistor configurations you can install:
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Infoprint 6500 User's Manual
Table 9. Terminating Resistor Configurations
Configuration
Factory Default
Alternate 1
Alternate 2
RP1 Default: 470 ohm
Alt 1: 220 ohm
Alt 2: 1K ohm
RP2 Default: 1K ohm
Alt 1: 330 ohm
Alt 2: none
Pull-Up (RP1)
470 ohm
220 ohm
1K ohm
Pull-Down (RP2)
1K ohm
330 ohm
none