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11. TECHNICAL APPENDIX
DXC-C33/C33P Product Information Manual
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29
Functions using WEN pulse — Output signal to external frame memory
The DXC-C33/C33P puts out a WEN pulse that enables the external frame memory to minutely
store the video signal output. The timing of the external frame memory can be locked by the HD/VD
signal or the sync signal of the DXC-C33/C33P so that the write-start timing of the external frame
memory can be precisely controlled. In short, the output pulse is effective for the video signal just
after the end of this pulse. The WEN pulse is useful to connect a frame grabber board or video printer
for the Strobe and Long-Term Exposure functions. Using the WEN pulse, users can capture full-frame
still images easily.
Signal specifications of the output pulse
• Output terminal: The 7th pin of the D-sub connector
• Output signal: The polarity of the pulse is switchable, and the signal is 75 ohms, unbalanced.
• Pulse width: 1V(one field)
The DXC-C33/C33P has three pulse modes: WEN-NORM, Strobe and Long term exposure.
1. WEN-NORM mode
The WEN pulse is continuously puts out a high signal in an even field, a low signal in an odd field (see
diagram) or vice versa. This means that the output pulse is a field index pulse.
2. Strobe mode
When the DXC-C33/C33P is set to the Strobe mode, the type of WEN pulse used is WEN-ODD only. The
WEN pulse is useful when used as a trigger for external frame memory to precisely capture full frame.
3. Long-Term exposure mode (WEN-EVEN mode and polarity rising edge)
During the Long-Term exposure mode, the video signal is output, as shown in the diagram below and the
WEN pulse is output in one the field before the valid video field outputs (see diagram). The shutter speed
must be set before the mode is selected.
WEN
Video
On-1 En-1 On En On En On-1 En-1 On-1 En-1En-1
In case of 2 FRM, shutter speed
Note: It is impossible to use both the Strobe mode and the Long-Term exposure mode at the same time.
WEN
Video
OEOEOEOEOEOE
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