User`s guide

30 Playlists
interprets this command according to the table in the General Command
Summary section and causes Video #1 to play.
Now that Video #1 is playing, the playlist will not advance to the next command
until that video is done playing. When the video is complete, the playlist will
advance to the next command (2PL) and do the exact same thing. After the
completion of Video #2, the playlist will encounter the ‘<’ operator, causing the
playlist to start over at the beginning.
Playlist Example using ‘AND’ operator
;play a series of videos and sends corresponding strings out of the Serial
Port
; Play Monkey Video and send a serial string
5PL AND MonkeyVideoSS
; Play Cheetah Video
6PL AND CheetahVideoSS
; Repeat
<
This example shows how the AND operator can be used. To understand why,
think back to the last example. Remember that a command is not executed until
the command prior to it has completed. Now, looking at the current example,
we need to do 2 things simultaneously. We need to play a video and send a
serial string at the same time, but we do not want to wait until the video is over
before sending the string. This is where the AND operator becomes useful.
By placing the AND operator between commands, we can instruct the playlist
engine to execute those commands without waiting for the others to complete.
This causes the playlist engine to execute all of these commands simultaneously,
and then wait for all of them to complete before it advances.
To understand this concept, let’s step through the example above. First, the
playlist engine sees the 5PL command. Just like before, it sends the command
to the Command Engine to start playback. At this point, the playlist would
normally wait for the video to complete before doing anything else. However,
since an AND operator is present after the current command, the playlist engine
executes that command immediately after the play command. The playlist
engine will now wait for both of these commands to finish before moving on to
the next command.
NOTE: The AND operator can be used more than once if needed. You can
execute any number of commands simultaneously if needed.