Chapter 6: NCR 7454 4x20 Customer Display 6-11
Set Screen Save Blank
Format: 1B 09
Description: This command is intended to preserve the life of the display hardware
unit. The firmware maintains a five-minute timer that triggers this
feature. The Screen Save feature can be disabled through a command
from the host software. When the feature is not disabled, two specific
options exist. The Set Screen Save Blank operation causes the display to
go blank when the timer expires. When the firmware receives the
command code, the Screen Save mode is canceled and the five-minute
timer is established. Screen Save Blank removes power from the Retail
VFD and does not refresh the display in the same manner as the Set
Low Power On command. At power up, the timer is established at five
minutes and Screen Save Blank is established as a default. The five
minute timer is not reset by any invalid or incorrect command.
Set Screen Save Walk
Format: 1B 0A
Description: This command causes the visible display to walk right to left when the
Screen Save timer expires (five minutes). The characters on the display
will appear to walk across the corresponding display row from right to
left. The four lines in the 4x20 Display will walk in parallel completely
off the left side of the display and then the four lines will appear to
come back from the right. If the display is space filled, then no effect is
perceived even though the walking is taking place. The Screen Save
Blank mode is the default mode after power up.
Turn On Screen Save
Format: 1B 0B
Description: This command causes the one of the screen save functions (Set Screen
Save Blank or Set Screen Save Walk) to activate immediately rather
than waiting for the screen save timer to expire. If the Disable Screen
Save Option command is in effect when this command is issued, it is
canceled and the screen saver is enabled and activated immediately.
