JAI RM-2030CL, User Manual

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TM/TMC/RM/RMC-2030CL
30 Operation
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If the exposure time is less than one frame time, the maximum trigger frequency is equal to 1/1
frame time.
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If the exposure time is longer than one frame time, the maximum trigger frequency is equal to
1/exposure time.
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The minimum active period of the external trigger is 5 μ s.
Figure 45. Asynchronous Programmable External Trigger
5.5.4 Pulse Width Control Mode
In Pulse Width Control (PWC) Mode, the exposure time is controlled by the external trigger. When an external
trigger is applied, one discharge signal (Vsub) is generated right after the active edge of the trigger. The
exposure starts when the discharge signal is in the off state. The exposure is off following the trigger active
off. Exposure time is controlled by the pulse width of the external trigger. Because the CCD requires some
overhead from trigger active off to the transfer gate event, the actual exposure time is equal to:
Exposure Time = Pulse Width +12.4 μ s
Since one discharge signal (Vsub) is generated right after the active edge of the trigger, it is asynchronous with
LDV, and the discharge signal may happen during an active video transfer period, visible reset noise may show
in the current image. To avoid reset noise, the maximum trigger frequency in PWC mode should be less than 1/
(exposure time + one frame transferring time).
The minimum active period of the external trigger is 5?s. Theoretically, the maximum active period of the
external trigger is unlimited. But, due to the usability of images at 25oC it is recommended the active period of
the external trigger be no longer than one second.