version 2.0 rev 18 Feb 2021
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2.6.2.11 Rolling Shutter Global Clear External Exposure Triggering (Non-
Overlap Mode) - Zyla 4.2 Only
While waiting on the trigger event, the sensor is held in a Global Clear State which ensures that charge build up
on the sensor is kept to a minimum while waiting for the trigger event. The ARM signal is asserted to indicate it
is ready to detect an incoming trigger input.
Once the external trigger input goes HIGH, Global Clear goes LOW and the exposure begins.
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 Row 1, and is coincident with the exposure
time for Row 1. The end of exposure for Row 2 will be delayed by one row time relative to Row 1, Row 3 will be
delayed by one row relative to Row 2 and so forth for the remaining rows, hence the exposure time for each row
is different as all rows have the same exposure start point in time but different exposure end times.
The
period of the external trigger pulse
defines the overall cycle time. If the width of the trigger event is less
than the frame read out time, the falling edge will be missed and a subsequent falling edge will be required to
end the exposure.
Figure 25: Rolling Shutter Global Clear External Exposure Triggering (Non-Overlap Mode) - Zyla 4.2
Table 20:
Rolling Shutter External Exposure Triggering (Non Overlap Mode) Timing Parameters - Zyla 4.2
Parameter
Minimum
Maximum
Exposure*
1 Frame + 1 Row
30s
Cycle Time (EXT Trig Period)
Ex 1 Frame + 5 Rows
-
External Start Delay
0
1 Row
EXT Trig Pulse Width
1 Frame + 1 Row
30 s
*The exposure time reported is the exposure time for ROW 1 and the period for which FIRE ALL is HIGH.
Summary of Contents for Zyla sCMOS 4.2 PLUS
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