Basler acA2000-165, Руководство пользователя

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Image Acquisition Control AW00123402000
116 Basler ace USB 3.0
For more information about the exposure active output signal, see Section 6.8.1 on page 127 .
For more information about the Exposure Time parameter, see Section 6.5 on page 110 .
For more information about the flash window, see Section 6.6.2.1 on page 118 .
Global Reset Release Mode
The global reset release mode is a variant of the electronic rolling shutter mode.
When the shutter is operating in global reset release mode, all of the lines in the sensor reset and
begin exposing when frame start is triggered. However, in the end of exposure, there is a temporal
offset (designated as tRow; see Table 23 on
page 114 ) from one line to the next. The exposure time
for line one is determined by the Exposure Time parameter setting. The exposure for line two will
end tRow after the exposure ends for line one. The exposure for line three will end tRow after the
exposure ends for line two. And so on until the bottom line of pixels is reached (see Figure 51).
The pixel values for each line are read out at the end of exposure time for the line. The readout time
for each line is also equal to tRow.
The Sensor Readout Time is the sum of the readout times of all lines. The Total Readout Time
equals the Sensor Readout Time plus the Exposure Overhead time C
1
.
Camera Model Exposure Overhead C
1
[µs]
acA1920-25um/uc 810 µs
acA2500-14um/uc 810 µs
acA3800-14um/uc TBD µs
acA4600-10uc TBD µs
Table 25: Temporal Shift for Start of Exposure Between Two Consecutive Lines
If you want to use a flash window the global reset release mode gives you
advantages over using the electronic rolling shutter mode:

In global reset release mode the flash window width extends over the entire
exposure time of a line in the sensor. In electronic rolling shutter mode,
however, the flash window width can only extend over part of exposure time
of a sensor’s line (compare
Figure 53 and Figure 52 ). Therefore, at a given
(high) frame rate, the global reset release mode allows for longer useful
exposure times.

In global reset release mode the flash window opens immediately after the
frame start trigger has occurred. For switching a flash on and off you
therefore do not have to wait and do not depend on the flash window signal
but can use the Exposure Active signal instead, if available. For more
information about the Exposure Active signal, see Section 6.8.1 on
page 127 .