Expression 3 - ETC

Output level conventions
The console uses both a highest level, or pile-on, convention and a last
action convention to determine levels for channels affected by more than
one control. Channels may be defined to operate with either convention.
HTP channels
The behavior of a pile-on channel is defined by the Highest Takes
Precedence (HTP) rule. The console reads all output levels it receives for
an HTP channel and sets that channel to the highest of them. A channel
controlled by a submaster always obeys the HTP rule, but the Blackout
key, Grandmaster control and parked channels all have priority over levels
set from the keypad.
For example, if an HTP channel is included in both a submaster and a cue
that has played back and is in a fader, the console sets the channel at the
higher of the two levels. Or, you may use the keypad to select that
channel and set it to any level, regardless of the levels set either by the
cue or the submaster.
HTP channels in the console are called “normal” channels.
LTP Channels
Channels may also be defined in the console to follow the Latest Takes
Precedence (LTP) rule. An LTP channel obeys the latest command to set
its level. When the command is to fade to a level, an LTP channel can fade
either in a physical fader (in the foreground) or in a background fader. Each
LTP channel has its own background fader.
An LTP channel fades in the foreground if its level moves to a new level
in the next cue. When a channel is fading in the foreground and no change
in that channel is commanded by the next cue, the fade continues in the
background. A cue stops running in the background when the last of its
channels stops fading in the background. Up to 600 cues may run in the
background at once.
For example, consider three cues recorded for channels Chan 1, Chan 2
and Chan 3, all of which are set as LTP channels. The cues contain
percentage levels for these three channels as follows:
Chan 1 Chan 2 Chan 3
Cue 1 25 0 0
Cue 2 25 50 0
Cue 3 50 50 50
• When Cue 1 starts, channel Chan 1 starts fading to level 25 with Cue
1 timing.
• If Cue 2 starts before Cue 1 ends, channel Chan 1 continues fading in
the background with Cue 1 timing and channel Chan 2 starts fading in
the foreground to level 50 with Cue 2 timing.
• If Cue 3 starts before Cue 2 ends, channels Chan 1 and Chan 3 start
fading in the foreground to level 50 with Cue 3 timing; channel Chan
2 continues fading in the background with Cue 2 timing.
4 Chapter 1 Introduction