User`s guide

Real Time Scheduler 77
Scheduler
Power-Up Behavior
At power up, the DVM2 begins playback of any playlist zero (ply00000.lst) or
video zero (vid00000.mpg) that is in the root directory of the drive. After this,
the schedule is loaded. The scheduler incorporates a “ look back” feature, which
allows the schedule to continue to operate, even after a power loss. It does this
in several ways:
If an item was scheduled for the fifteen-minute block in which the unit was
powered up, that item is immediately scheduled for playback.
If there is no item scheduled for the current fifteen-minute block, the scheduler
backs up to the last block that contained a scheduled item (this could be several
days before). If that last item was to loop a playlist, it is executed.
If a playlist or video zero was found and played on power up, then there is
already a clip playing when the “ look-back” is performed. This clip will be
allowed to finish before the scheduled item begins.
For example, suppose that there is a power loss at 3:00 PM on Saturday, that
there is a playlist zero that loops two videos, and that the last event in the
schedule prior to the restoration of power was at 9:00 AM on Saturday. On
power up, the first video in playlist zero will play to completion, then the event
scheduled for 9:00 AM will execute.
Seamless Transitions
The scheduler will never “Cut off” a video. If the unit is already playing video
when it is time to play a new scheduled item, the currently video will finish
before playback of the scheduled item begins. If the scheduled item is a single
video, the transition to this video is seamless; in other words, there is no still
frame delay between the videos while the second video is searched. If the
scheduled item is a playlist, the last frame of the previous video remains on-
screen approximately one fourth of a second while the DVM2 processes the
scheduled playlist.