Mod: Sw 1 And Mod: Sw 2 - Lexicon PCM 81 - REV 2 User Manual

Algorithms and Parameters
MODULATION
(continued)
Mod: Latch
(continued)
There is no output from the latch until the Src value falls within the
range defined by the settings of High and Low. While the source
value is between these thresholds, the output of the latch is the
same value as the source. When the source value reaches or passes
either threshold, the output of the latch holds at the limit value
until the source value passes through the threshold twice. The latch
can be set to hold at either the low threshold, the high threshold,
or both. Setting Low to 0 disables latching at the low threshold.
Setting High to 127 disables latching at the high threshold.
See preset P0 3.0 FSw2 Rotary as an example.

Mod: Sw 1 and Mod: Sw 2

These are identical time switches. Each has five parameters: Rate, P
Width, Mode, T Lvl and T Src.
• Rate Sets the speed at which the switch cycles. It
can be set in time values (such as 1.5 Hz) or
tempo values (such as 3:2 Cycles per Beat).
Simultaneously pressing Up and Tempo will
toggle these display options.
• P Width Determines the proportion of each switch
cycle during which the switch is on. For
example, setting P Width to 50% means that
the switch is on for one-half of a cycle.
3-24
• Mode Determines the "shape" of the switch output.
Three settings are available: Switch, Ramp,
and Off. When Switch is selected, the
transition from on to off is instantaneous, i.e.
the switch output resembles a pulse wave.
When Ramp is selected, the transition from on
to off is continuous, i.e. the switch output
resembles a triangle or sawtooth wave.
• Off Turns the switch off (and frees up processor
time). To optimize PCM 81 real-time response,
set switch to Off when it is not being used.
• T Lvl Sets the threshold value at which the switch
will begin to cycle.
• T Src Selects a patch source to drive the switch. The
output of the switch is 0 as long as T Src is set
to a value below T Lvl. Once the source value
reaches or passes T Lvl, the switch will begin to
cycle between on (127) and off (0) at the
speed set by Rate.
Note that both Rate and P Width are available as patch
Destinations, allowing them to be dynamically controlled by other
patch sources. Switches are reset to the beginning of their cycles
whenever Tap is pressed.
A special, composite output of these switches, called Sw 1&2 is
available as a patch source. The value of Sw 1&2 alternates
between the output of Sw 1 and the output of Sw 2. The
alternation occurs on the transition from on to off. Note that both
Sw 1 and Sw 2 must be active for the alternation to occur.
Lexicon