Fastec IL3, Руководство оператора

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IL3 User’s Guide
page 64
11S-3002B
Application Note 3: Trigger Position and the Circular Buffer
Capturing a high-speed event can be a tricky proposition. Often high speed events that we are
interested in happen without warning. Other times high speed events are tightly controlled. The TS3
is designed to handle myriad scenarios. Here are several examples:
Example 1: Someone is blowing up a balloon until it pops. You want to capture the balloon pop. You
have a partition of memory with one second of record time. It is very difficult to estimate within a
second when that balloon is going to pop!
Example 2: Jams happen once or twice a day on an automated production line. When they occur,
they may set off a chain of events that you would like to capture. The jam is detected by sensors on
the machinery that is propagated to various parts of the line. You need to image the time just before
the jam occurred to help understand the cause. You are equally as interested to capture the time just
after the event to understand how the equipment reacted to the jam.
Example 3: You would like to image the launch of a missile. You have ample warning when ignition is
to happen. There is a long count down. There may even be a signal available at launch time.
In order to capture events like the ones in the examples above, the TS3 uses a circular image buffer
that is able to capture high speed imagery indefinitely, though it may only be able to retain a few
seconds at a time. The figure below is a representation of a circular buffer. First the empty buffer is
seen with 20 empty slots for images. The second graphic shows the first four frames. With each frame
added, the older images are shifted up, the newest ones added at the bottom.
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Figure 7-5: Circular Buffer Fills and Images Shift Position