JAI CV-A11 사용자 설명서

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CV-A11
 
6.6. Pulse Width Control Mode  
The leading edge of the trigger pulse initiates the capture. The exposure time (accumulation 
time) is governed by the duration of the trigger pulse. If the polarity of this pulse is reversed, 
the camera can be configured to correct for it. 
The exposure time range is 1.5H to 1000H (shortest and longest pulse duration). 
 
To use this mode: 
Set function: 
Trigger mode to “Pulse Width Control” 
TR=2 
     HD 
accumulation 
 
HC=0, 
HC=1 
 
 
 
 
 
Polarity and other functions 
 
Input:   
 
Ext. trigger to pin 5 on 6 pin connector (or 11 on 12 pin connector) 
 
 
 
 
Ext. HD to pin 6 on 12 pin connector. (If used).  
 
 
Fig. 18. Pulse width control.
 
 
Important notes on using this mode:
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•  The exposure will start and stop synchronized to the internal H signal. It result in 1H 
jitter. To avoid this jitter, synchronize the camera with an external HD and make sure 
that the trigger pulse aligns to the HD signal as shown in Fig. 14. 
•  This trigger mode is also supported by a function called “HD Asynchronous 
Accumulation”, ACSII command “HC”. This function allows integration to start 
immediately at the leading (falling) edge of the Ext. Trig pulse instead of at the next 
horizontal drive pulse HD. Please refer to fig. 15 and fig. 16. To enable this function, set 
HC=1. (Factory default is HC=0). If the falling edge of the trigger falls inside the HD low 
pulse, a jitter up to 7.5µsec. can be expected. The exposure will start up to 7.5µsec. 
after the falling edge of the  trigger. 
•  In HD asynchronous PWC mode avoid the trigger to raise inside the HD low period. It will 
cause 1 line image position jitter. 
•  Please note that the timing chart in Fig. 18 only shows the HD synchronous mode. 
• 
Do not input external VD signal at Pin No. 7 of the 12-pin Hirose connector, as it may 
disturb the external trigger function.
 
•  Do not input a new trigger before the previous video is read out. (WEN is high). 
 
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