Photron FASTCAM SA-Z, Hardware Manual

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Chapter. 3 Recording
3.8.10. RANDOM LOOP Mode
RANDOM LOOP mode is a trigger mode, similar to RANDOM MODE, where each time a trigger is
input, only a predetermined number of frames are saved in memory. The difference is that RANDOM
LOOP mode continues framing, by using the memory as a loop memory unit, until the trigger input is
cut off to stop framing.
When a recording of the predetermined number of frames ends, and if the number of frames
remaining in memory to be recorded is smaller than the predetermined number, the system goes
back to the first frame of the memory and starts overwriting the image data that was written in the
previous recording cycle.
For example, suppose a duration for a RANDOM FRAME recording is predetermined 1000 frames
on a system with a memory capacity of 3500 frames, and four trigger inputs are given.
For example, the recordable memory capacity is 3,500 frames, the frame number for each
RANDOM trigger is 1,000 freames, and the number of trigger times is 4. In this case, the number of
frames recorded reaches 3,000 after the third trigger, with 500 frames remaining unused in the
memory. The system, without recording image data in the remaining 500 frames, goes back to the
first frame of the memory and starts overwriting
The overwriting sequence is therefore:
1st 1,000
⇒
2nd 1,000
⇒
3rd 1,000
⇒
1st 1,000
⇒
2nd 1.000 etc.
with the last 500 frames always remaining unused (see the below illustration).
The number of frames to be recorded with one trigger can be set to any number from 1 (one) up to
the maximum number of frames available to record in the memory.
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