version 2.0 rev 18 Feb 2021
52
2.6.3.7  Global Shutter Triggering Constraints
The table below shows a summary of constraints when operating the Zyla 5.5 model in Global Shutter mode:
Table 32: Global Shutter Mode Triggering Constraints
Global Shutter Triggering Modes Exposure Range
max 
trigger 
Jitter
Min 
trigger 
pulse 
width
Fast 
exposure 
switching 
supported
Internal
(Non Overlap)
User settable exposure time and Cycle Time
Short Exp: 1 Row to (1 Frame + 3 Rows)
Long Exp:  (1 Frame + 4 Rows) to 30 s
1 Frame
1 Row
-
-
√
√
Internal Overlap
(Overlap On)
User settable exposure time
(1 Frame + 1 InterFrame + 1 Row) to 
30 s
1 Row -
√
External/Software
(Non Overlap)
User settable exposure Time. Cycle Time 
controlled via period of external trigger 
pulse
(1 Frame + 4 Rows) to 30 s
1 Row
2 Sen-
sor 
Clocks
√
External/Software
(Overlap On)
User settable exposure time. Cycle Time 
controlled via software trigger function
(1 Frame + 1 InterFrame + 1 Row) to 
30 s
1 Row
2 Sen-
sor 
Clocks
√
External Exposure 
(Non Overlap)
Exposure Time controlled by width of exter
-
nal trigger pulse. 
Cycle Time controlled via period of external 
trigger pulse.
(1 Frame + 3 Rows) to 30 s
1 Row
1 Frame 
+ 
3 Rows
x
External Exposure 
(Overlap On)
Exposure time controlled by period of 
+
ve 
edge of external trigger pulses. Cycle Time is 
exposure time
(2 Frames + 2 InterFrames) to 30 s
1 Row
2 Sen-
sor 
Clocks
x
External Start
(Non Overlap)
User settable exposure time and Cycle Time 
butsequenceinitializedviaexternaltrigger
pulse
Short Exp: 1 Row to (1 Frame + 3 Rows)
Long Exp: (1 Frame + 4 Rows) to 30 s
1 Frame
1 Row
2 Sen-
sor 
Clocks
√
√
External Start
(Overlap On)
User settable exposure time (1 Frame + 1 InterFrame + 1 Row) + 30 s
1 Row
2 Sen-
sor 
Clocks
√
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), i.e. depends on readout rate.
3. 1Frameistheimageheightofasensorhalf,denedinRowsanddeterminedbytheROIcongured,
 e.g.fullframe=1080.Thisisthenumberofrowsthatisreadoutbyeachsensorhalf.Theframe
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).
6.  Image acquisition must be stopped to change between short and long exposures. Fast Exposure 
Switching can occur in the triggering modes shown above but the exposure time is then limited to the 
exposure range shown for each sequence.