IAI CV-M77, Operation Manual

Page: 14 / 32

CV-M77
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6.4.3. Frame Delay Readout EPS
This trigger mode operates in H non-reset mode. In H non-reset mode the exposure will start at
the first internal HD after the trigger. The trigger input should be longer than or equal to 2 HD
(102
µ
sec.). The external trigger pulse initiates the capture, and the exposure time
(accumulation time) is governed by the fixed shutter speed set up by the rear panel DIP-switches
or via RS-232C control. The EEN pulse indicates the actual exposure time.
The resulting video signal will first start to be read out after the input of an external VD signal.
The readout delay should not be to long due to visible dark current noise generated in the CCD
sensor. The WEN pulse indicates the start of valid video signal. Refer to timing charts for details.
A new trigger pulse must not be applied before the video read out has finished.
If the camera is synchronized to an external HD signal, there are some requirements to the
phase between the ext. HD and the Ext. trigger. The falling edge of the trigger should be less
than 8
µ
sec before the falling edge of the ext. HD and less than 2
µ
sec after the falling edge of
the ext. HD (see fig. 14.). Otherwise the jitter will be too high.
Mode setting and all other settings can be done via RS 232C control if rear switch SW1-10 is ON.
Mode setting and some other settings can be done by switch if rear switch SW1-10 is OFF.
For details: refer to “7. Configuring the Camera”.
To use this mode:
RS SW1-
Set function: Trigger mode to “Fame Delayed readout EPS” TR=3 1 ON, 2 OFF, 3 ON
Shutter to “Normal” or “Programmable” SM=0, SM=1
“Shutter speed” SH=0 through 11 1, 2, 3, 4
“Programmable exposure” PE=3 through 791
Polarity and other functions
Input: Ext. trigger in on pin 5 on 6-pin con. (Or 11 on 12 pin). 4.0 Vp-p ±2.0V.
Ext VD on pin 7 on 12 pin con. (Or 1 on 9 pin ). 4.0 Vp-p ±2.0V.
Ext. HD in on pin 6 on 12-pin connector. 4.0 Vp-p ±2.0V. (If used).
Important notes on using this mode
•
The start of exposure will start synchronized to the internal H signal. The start may be
shifted max 1H. To avoid this shift (1H jitter), synchronize the camera to an external HD
and make sure that the trigger pulse aligns to the HD as shown in fig. 14.
•
The trigger pulse width should be >2H to <2000H.
•
External sync system should follow the camera scanning system.
•
A new trigger must not be applied before WEN is high.
Fig. 17. Vertical timing for Frame Delay readout EPS