Revision 1 - Printed
April 10, 1997
15" Plus Manual
17
SPEED CONTROL FROM DMX
The ability to control the maximum gel speed is important for smooth
scrolling between colours and consistently quiet colour changes
irrespective of the limits of the incoming DMX control signal. Where
required, the processor calculates fades using 12 bit levels which
avoids the 'stepping' associated with 8-bit DMX signals. This is especially
critical for slow fades on long gel strings and larger colour changers
(15", 22", 26" etc)
When using speed control, the 12-bit fade resolution is only
effective if the PlusCard fade time is
longer
than the control
signal fade. Where speed control is required from the PlusCard,
the best results will be achieved if the position channel changes
with time 0 and the time information is sent on the separate
channel.
If power is disconnected and reconnected to the Rainbow, the
PlusCard will hold the last good DMX value. Once it receives a
new valid level, it will fade at medium speed to achieve this level.
When the gel position matches the input level, the PlusCard
resumes normal operation. This prevents the colour changers
racing to a level if the power or data is accidentally lost.