Input triggers have some special considerations
when using the new Edit LUT Feature. As previously noted, Pattern 3
(Matt) has an input trigger associated. When a trigger is added to a
pattern, the pattern preceding, Pattern 2 (Sue) in this case, has an
all-black pattern loaded at the very end. While the sequence is waiting for the
trigger, the sequence does not have a pattern displaying during the wait. This
attribute follows Pattern 2 during a reorder. In the example, the first entry
(Pattern 2) in the new display order has a 105µs dark pattern at the end. If
Pattern 0 (Bob) is placed in front of Pattern 3 (Matt - the triggered
pattern), then the last bit-pattern of Pattern 0 (Bob) continues to display
in our new display order while waiting for the trigger in Pattern 3
(Matt).
The unwanted trigger behavior can be compensated for by one the following
methods:
- Method 1: Consider
Pattern 2 and 3 (Sue and Matt) as a set that must always be
moved together in the new display order.
- - Method 1 is the simplest, but the tradeoff is that these two
patterns are not separable without the undesired trigger behavior
described above.
- Method 2: Add a 1-bit
all-black pattern with the shortest duration allowed for most DMDs preceding
the trigger pattern. See Minimum Exposure in Any Pattern Mode in the DLPC900 Programmer's Guide for details. Now, consider this
pattern and the triggered pattern following as a set that must always be
moved together.
- - Method 2 is more versatile, but the pattern set must always
contain a triggered pattern.
- Method 3: Add a 1-bit
all-black pattern with the shortest duration allowed followed by a triggered
1-bit all-black pattern, and remove the trigger from the actual pattern of
interest. These two patterns are now a versatile trigger set that can be
used repeatedly wherever a trigger is desired. Note, that since the
triggered pattern is black, even if the exposure integration begins with the
triggered black pattern there is no light contributing to the exposure.
- - Method 3 is the most versatile since this standalone trigger set
only has to be placed in the Pattern Index set (on the Pattern Mode
page) once but can be used in many positions when defining a new
display order.