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2.6.2.6 Rolling Shutter External Exposure Triggering (Non-Overlap Mode)
While waiting on the trigger event, the sensor held in a global clear state and is put into a “pre-scan read out
cycle”. On detection of the trigger event, Global Clear goes LOW and a frame read out is initiated. This frame
is discarded as it does not contain the correct exposure period. Reading out a frame effectively begins a new
exposure. When the external trigger input goes LOW, a signal frame read out phase begins. When the frame
has been read out completely, the Global Clear is held HIGH until the next trigger event is detected.
The external trigger pulse width defines the exposure time for all rows, but is only coincident with the exposure
time for Row 1. The exposure for Row 2 will be delayed by one row time relative to Row 1 and so forth.
The period of the external trigger pulse defines the overall cycle time. If the width of the trigger event is
less than 3 Rows, the falling edge will be missed and a subsequent falling edge will be required to end the
exposure.
Figure 20:
Rolling Shutter External Exposure Triggering (Non Overlap Mode)
Table 16:
Rolling Shutter External Exposure Triggering (Non Overlap Mode) Timing Parameters
Parameter
Minimum
Maximum
Exposure
3 Rows
30 s
Cycle Time (EXT Trig Period)
Ex 1 Frame + 1 Row
-
External Start Delay
0
1 Row
EXT Trig Pulse Width
3 Rows
30 s
Summary of Contents for Zyla sCMOS 4.2 PLUS
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