NAC Image Technology ST-839, Руководство пользователя

Страница: 124 / 370

Set Variable Frame Rates
Set Variable Frame Rates
The variable frame rate function (DUALRATE) is a function making the frame rate variable before and after
the trigger. With a speed ratio (RATIO) during low speed recording, the number of frames (BASERATE) during
normal recording is set.
4-26
(00400)
This is a function to record at a frame rate set with only the designated frame rate and to conduct low speed
recording before trigger input and after the designated number of frames. This setting is enabled when the
event recorded extends over a long period of time but a certain instant is recorded at a high speed, and when
recording an entire event over a long period of time.
The speed ratio during low speed recording can be set at a fraction of the normal recording, with a setting
range of 2 ~ 100.
Low speed recording is performed until the trigger is input, and recording is conducted at a normal speed only
for the frames set after the trigger. After recording the set number of frames, if there is more memory,
further recording can be performed at a low speed, until there is no more memory.
The following figure shows the operation with the frame rate is 5000 frames/sec, the normal frame rate
frame rate is 2501 frames (about 500ms) and the recording ratio at low speed is 1/5
th
of 1000 frames/sec.

EPO (exposure pulse output) outputs exposure pulses at a low frame rate that is the same as
the normal frame rate.

The variable frame rate function is disabled during burst recording.

During normal recording, the frame rate uses the FRM RATE (

A
4-7)set values.
Variable Frame Rate Function