version 2.0 rev 18 Feb 2021
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2.6.2.12 Rolling Shutter Triggering Constraints
The table below shows a summary of constraints when operating in Rolling Shutter mode:
Table 21: Rolling Shutter Mode Triggering Constraints
Rolling Shutter Triggering Modes Exposure Range
Max 
trigger 
Jitter
Min 
trigger 
pulse 
width
Fast 
exposure 
switching 
supported
Internal
(Non Overlap)
User settable exposure time. User settable 
Cycle Time.
1 Row to 30 s - - √
Internal Overlap
(Overlap On)
User settable exposure time. 1 Row to 30 s - - √
External
(Non Overlap)
Exposure time user settable. Cycle Time 
controlled via external trigger pulse
3 Rows to 30 s 1 Row
2 Sensor 
Clocks
√
Software
(Non Overlap)
Exposure time user settable. Cycle Time 
controlled via software trigger function
3 Rows to 30s 1 Row
2 Sensor 
Clocks
√
External Exposure 
(Non Overlap)
Exposure Time controlled by width of 
external trigger pulse. Cycle Time controlled 
via period of external trigger pulse. 
3 Rows to 30s 1 Row
2 Sensor 
Clocks
x
External Exposure 
(Overlap On)
Exposure time controlled by period of exter-
nal trigger pulse
(1 Frame + 1 Row) to 30 s 1 Row
2 Sensor 
Clocks
x
External Start
(Non Overlap)
User settable exposure time. User settable 
Cycle Time.
1 Row to 30 s
2 Frames
1 Row
2 Sensor 
Clocks
√
Global Clear- Internal
(Non Overlap)
User settable exposure time. Cycle Time 
is read out time for short exposures. User 
settable Cycle time for long exposures. Zyla 
4.2 only.
(1 Frame + 1 Row) to 30 s 1 Row - √
Global Clear External/
Software Triggering 
(Non-Overlap)
Exposure time user settable. Cycle Time 
controlled via period of external trigger 
pulse. Zyla 4.2 only.
(1 Frame + 1 Row) to 30 s 1 Row
2 Sensor 
Clocks
√
Global Clear External 
Exposure
 (Non-Overlap) 
Exposure Time controlled by width of exter-
nal trigger pulse. 
Cycle Time controlled via period of external 
trigger pulse. Zyla 4.2 only.
(1 Frame + 1 Row) to 30 s 1 Row
1 Frame + 
1 Row
√
NOTES:
1. 
Exposure Time granularity for all modes is sensor row based so the exposure time in the dialog will always be 
rounded to the nearest integer number of row readout times.
2.  1 Row is the time taken to perform a full row readout (2624 clock cycles Zyla 5.5; 2592 clock cycles Zyla 4.2), i.e. 
depends on readout rate.
3. 1Frameistheimageheightofasensorhalf,denedinRowsanddeterminedbytheROIcongured,e.g.fullframe.
This is the number of rows that is read out by each sensor half. The frame readout time for any ROI can be requested 
via SDK function. (Refer to SDK3 User Guide for details).
4. 
A short exposure is referred to an exposure that is less than a Frame Readout Time. (Depends on ROI selected).
5.  A long exposure is referred to an exposure time that is greater than a Frame Readout Time. (Depends on ROI 
selected).