Horner APG XL7 OCS - Manual (Page 71)

XL7 User Manual
The currently selected entry is indicated by a yellow highlight which can be moved up or down by
touching the arrow buttons or by directly touching an entry. If more entries exist than can fit on the
page, a scroll bar is displayed on the right side that also indicates the current relative position.
File operations are accomplished by pressing the appropriate button at the bottom of the removable
media viewer. The configuration of the removable media object that invokes the removable media
viewer defines what buttons are enabled and available to the user. A button is grayed and does not
respond to touch if configured as disabled.
The (Enter) button (if enabled) performs certain operations based on the selected file’s type:
.. change display to parent directory
change display to child directory
bmp, jpeg display bitmap (if compatible format)
pgm load application (if compatible model and version)
Alternately, the (enter) button can be configured to simply load the ASCII representation of the file path
(including the file name) to a group of OCS registers. That pathname can then be used by ladder for
opening and manipulating that file.
Once view operations are complete, simply touch the Esc button to remove the pop-up removable
media viewer.
If the removable media is used in an application, the removable media device requires changing by the
operator, and the application is attempting to write to the removable media when it is removed, the
screen designer should create objects that allow the operator to temporally halt access to the
removable media. This prevents corruption to the file system if the removable media is removed during
a file write sequence. The graphic objects should set OCS register %SR174.1 (when requesting the card
be removed) and provide an indicator based on OCS register %SR174.2 (which indicates that it is safe to
remove the removable media).
Figure 13.9 – Example application segment for safe removal of removable media
13.10 Screen Saver
The XL7 screen backlight life is typically 5 years when in continuous use. If the application does not
require interaction with the XL7 for long periods of time, the backlight life can be extended by using the
screen saver function. When enabled through the system menu, the backlight is shut off (screen goes
black) after a specified time of no touch activity on the screen. When the screen saver shuts off the
backlight, any operator touch on the screen or function keys reactivates the backlight.
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