Data Translation MACH Series, User Manual

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Principles of Operation
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Using software, you can specify the following:
• The width of the sync signals
−
The width of the horizontal sync
signal can range from 250 ns to 950,000,000 ns (nominal is 4,800
ns). The width of the vertical sync signal can range from 250 ns to
950,000,000 ns (nominal is 190,0 0 0ns for 6 0Hz image formats
and 160,000 ns for 50 Hz image formats).
• The frequency of the sync signals
−
The horizontal sync
frequency can range from 1 Hz to 2 MHz (nominal is 15.75 kHz
for 60 Hz image formats and 15.625 kHz for 50 Hz image
formats). The vertical sync frequency can range from 1 Hz to
200 kHz (nominal is 60 Hz for 60 Hz image formats and 50 Hz for
50 Hz image formats).
• The phase between the horizontal sync and vertical sync
signals
−
The phase is specified as a percentage of the horizontal
period multiplied by 100 and ranges from 100 (1%) to 9,900
(99%); nominal is 5,000 (50%).
With interlaced cameras that accept horizontal and vertical syncs,
you can adjust the phase to determine the field to output. By setting
up the DT3152-LS board as noninterlaced with a sync phase of 50%,
the even field is continuously selected. If the phase is 1%, the odd
field is continuously selected.
You can alternate the phase at each vertical sync by setting the phase
at 50% and setting up the DT3152-LS board as interlaced. The even
and odd fields are then alternately selected for a true interlaced
image. Whenever the board is set up as interlaced, the phase
alternates between 1% and whatever phase is specified. These
different setups are illustrated in
Figure 9 .