Exposure Time Control Modes In Detail - Basler WOOD BURNING FIREPLACE Wood Burning Fireplace

Basic Operation and Features

3.3 Exposure Time Control Modes in Detail

This section is aimed at system integrators or engineers who intend to develop their own
framegrabbers or preprocessing. If you are using a commercially available framegrabber, the
framegrabber takes care of the different timings described in this section without the need for any
action by you.
Depending on the frame rate and exposure time determined by setting the ExSync signal or the
Timer 1 and Timer 2 values, the timing of the exposure control signals differs. There are four
different timings and the camera switches between these four timings automatically. The timings
are labelled asynchronous timing, synchronous/asynchronous timing, synchronous timing 1, and
synchronous timing 2.
Asynchronous timing operates the camera with "non-overlapped" exposure. In this case each time
a frame is captured, the camera completes the entire exposure/readout process before capture of
the next frame is triggered.
Synchronous/asynchronous timing, synchronous timing 1, and synchronous timing 2 operate the
camera with „overalapped" exposure. In this case the exposure of frame N+1 is triggered before
the readout of frame N is complete.
This introductory section contains formulas that describe the conditions for the cam-
era to enter the four timings. The formulas were generalized as much as possible,
but the figures were taken from the Free-run mode. They can be different in other
exposure time control modes.
For detailed information, see the detailed timings described in sections
3.3.4.
Frame Valid High is 2000 µs for the A504
for the A501
Frame Period
• Asynchronous Timing: This is the slowest timing. This timing is always used for the first
image. You can realize a long exposure time with this timing. Exposure and readout are per-
formed sequentially. Exposure of frame N+1 starts after readout of frame N while frame valid
is low. Readout of frame N+1 is triggered after readout of frame N while frame valid is low.
To let the camera operate in this timing, set the frame rate and the exposure time so that the
following condition is met:
The asynchronous timing is described in more detail in sections 3.3.1.1, 3.3.2.1, 3.3.3.1, and
3.3.4.1 for each exposure mode.
Synchronous/Asynchronous Timing: This timing is suitable for long exposure times.
Exposure of frame N+1 starts during readout of frame N while frame valid is high. Readout of
frame N+1 is triggered after readout of frame N while frame valid is low.
To let the camera operate with this timing, set the frame rate and the exposure time so that
the following conditions are met:
3-8
PRELIMINARY
.
k/kc
1
= ------------------------------ -
Frame Rate
Frame Period > Exposure Time + Frame Valid High
Frame Period < Exposure Time + Frame Valid High
Frame Period > Frame Valid High + 3 µs for A504k/kc (or 3.75 µs for A503k or
20.2 µs for A501k/kc)
2485 µs for the A503
k/kc,
3.3.1 through
and 13.517 ms
k
Basler A500
k