9
4. Timing Signals
4.1 Asynchronous Capture Mode (Shutter position from #1 to #8)
Make sure NRM/ASM switch is set to ASM mode and FLD/FRM switch is set to FLD mode.
The camera can be reset by providing an external vertical initialized pulse (VINT), see figure 9 shown below. The
VINT pulse width is recommended to be greater than 1H, or 63.5
µ
sec. Discharge occurs within 1H of VINT so
that external VINT will be latched with HD. There is almost no delay in capturing (delay is only < 1HD). XSUB,
the vertical substrate pulse, also locks with HD. The exposure or integration period is between the falling edges
of XSUB and XFER, the transfer gate pulse. This exposure time should match the shutter speed set on the rear
panel of the camera. For example, if the shutter speed on rear panel reads #1 (1/125), then the exposure should
be equal to 1/125 sec. Once XFER occurs, the new reset shutter video will appear. The camera only outputs one
vertical sync pulse reset; it is much easier for frame grabber to capture asynchronous Video.
Figure 9. Asynchronous Capture Timing
4.2 Pulse Width Shutter Control (Position #9)
Make sure NRM/ASM switch is set to ASM mode and FLD/FRM switch is set to FLD mode.
This pulse width shutter control is similar the normal asynchronous capture, except the shutter speed or exposure
time depends on the VINT pulse width, X. For example, if X = 3H according to figure 10 below, the exposure time
in this case is 3H or 0.19msec. The minimum exposure time is 1H or 63.5
µ
sec., and the maximum exposure
time can be up to a few frames without significant noise.
Figure 10. Pulse Width Timing
