Rolling Shutter (Aca2500Gm/Gc Only) - Basler ace acA640-90gm User Manual

7.7.2 Rolling Shutter
All acA2500-14gm/gc cameras are equipped with an electronic rolling shutter. The rolling shutter is
used to control the start and stop of sensor exposure. The rolling shutter used in these cameras has
two operating modes: electronic rolling shutter mode and global reset release mode.
Electronic Rolling Shutter Mode
When shutter is in the electronic rolling shutter (ERS) operating mode, it exposes and reads out the
pixel lines with a temporal offset (designated as tRow) from one line to the next. When frame start
is triggered, the camera resets the top line of pixels (line one) and begins exposing that line. The
camera resets line two tRow later and begins exposing the line. The camera resets line three tRow
later and begins exposing the line. And so on until the bottom line of pixels is reached (see
Figure 46).
The exposure time is the same for all lines and is determined by the Exposure Time Abs parameter
setting.
The pixel values for each line are read out at the end of exposure for the line. Because the readout
time for each line is also tRow, the temporal shift for the end of readout is identical to the temporal
shift for the start of exposure.
For the acA2500-14gm/gc, tRow = 35 µs.
Frame Start
Triggered
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11
Line N-2
Line N-1
Line N
Reset Runtime
Fig. 46: Rolling Shutter in the ERS Mode
Basler ace GigE
(acA2500gm/gc Only)
tRow
Total Runtime
Image Acquisition Control
Total Readout Time
tRow
= line exposure
= line readout
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