IBM 3274 User Manual page 87

Procedure 3: 3274, 3299, and 3274-to-3299 Link Check
Notes:
1.
Prerequisites for this procedure are an additional display
and an additional device cable.
2. If this is an installation problem or if the subsystem has
been recently reconfigured or recustomized, you should
review the Port Assignment Table, especially for any new
signal cable routings, the customization data (Configuration
Data Card) and process, and host programming, in addition
to using this procedure.
3. System operation problems can occur during swapping of
device signal cables if the device types are different, or if the
screen size or features of the devices are not the same.
DANGER
Never connect or disconnect device signal
cables during an electrical storm.
1. At the 3299, disconnect the signal cable that runs from the
3274 to the 3299 input connector. (See Figure 2-1
IJ
on
page 2-51.)
2. At the associated 3274 device panel, move the switch to the
up position, or connect the shorting cap, whichever is
appropriate. (See Figure 2-1
m
on page 2-51.)
3. Attach a working terminal (3178, 3278, 3279, or equivalent)
to the signal cable you have just disconnected from the
3299 input position. (See Figure 2-1
III
on page 2-51.)
4. Set the Normal/Test switch on the display to Test, then
back to Normal, or turn power off, then on, and wait up to
2 minutes, whichever is appropriate.
5. If a
D
symbol is now displayed, you have determined that
the fault is in the 3299, and you should follow the 3299
2-12