Version 1.0 rev 14 Aug 2019
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While waiting on the trigger event, the sensor is put into a “pre-scan read out cycle” which performs a continuous
Rolling Reset 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 trigger event is detected, a Rolling Reset is initiated. When the external trigger pulse goes LOW, a signal frame
read out phase begins. Once the frame has been read out completely the Arm signal goes high and the camera waits for
the next trigger event to be 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 2 rows,
the falling edge will be missed, and a subsequent falling edge will be required to end the exposure.
Figure 17: Rolling Shutter - External Exposure (Note exposure time can vary during series).
Table 8: Rolling Shutter External Exposure Triggering Timing Parameters.
Parameter
Minimum
Maximum
Exposure
2 Rows
3600 s
Cycle Time (EXT Trig Period)
Ex 1 Frame + 3 Row
-
EXT Trig Pulse Width
2 Rows
-
* True minimum exposure time is the quoted value + T
res
