IL3 User’s Guide
11S-3002B
page 45
Per Second:
Many commonly available sync sources have
a precision 1 Hz output. IRIG and GPS are
two that are very often used with high-
speed data capture.
The IL3 is able to utilize these signals for
synchronization of cameras at any frame
rate.
To use Per Second Synchronization:
1. Open the Record Controls tab and
locate the Sync In controls.
2. Click on the check box to enable Sync In.
3. Select “Per Second” in the dialog box.
The Master Frame rate and Rate Divisor fields will gray-out.
The camera will now record at whatever rate has been selected in the Record Settings tab, in this
case it is 506 fps. It will multiply the 1Hz Sync In pulse by 506 to clock the camera. In this manner it is
possible to synchronize several cameras, operating at different frame rates to one 1Hz signal.
Figure 5-3: Sync In Per Second
Per Frame Clock
Camera 1
Camera 2
6
∝
sec
Camera 3
The Frame Clock may be from another
Camera (See “5-3 Master/Slave Setup” on
page 47) or some other external clock.
Note: for each camera, the signal shown
represents the exposure (high = shutter
“open”)
Camera 1 is set for Falling Edge, at a 1x
shutter. Note that there is a 6
m
sec inter-
frame time.
Camera 2 is set for Falling Edge, at a 2x
shutter. Note that exposures for Camera 1
and Camera 2 begin at the same time.
Camera 3 is set for Rising Edge, a 4x
shutter and has a rate divisor of 3.
Figure 5-2: Sync: Per Frame Timing
