Basler A640F, Руководство пользователя

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Basic Operation & Standard Features
BASLER A640
f
3-7
DRAFT
3.2.5 Controlling Exposure Start with an ExTrig Signal
The external trigger (ExTrig) input signal can be used to control the start of exposure. A rising
edge or a falling edge of the signal can be used to trigger exposure start. The Trigger Mode control
register (see page
4-32 ) is used to enable ExTrig exposure start control, to select rising or falling
edge triggering, and to assign a physical input port to receive the ExTrig signal.
The ExTrig signal can be periodic or non-periodic. When the camera is operating under control of
an ExTrig signal, the period of the ExTrig signal determines the camera’s frame rate:
For example, if you are operating a camera with an ExTrig signal period of 110 ms (0.110 s):
So in this case, the frame rate is 9.1 fps.
The minimum high time for a rising edge trigger (or low time for a falling edge trigger) is 1 µs.
3.2.5.1 Available ExTrig Exposure Modes
If you are triggering the camera with an ExTrig signal, two exposure modes are available,
programmable mode and level controlled mode.
Programmable Exposure Mode
When programmable mode is selected, the length of the exposure is determined by the shutter
setting as described in Section
3.2.1 . If the camera is set for rising edge triggering, exposure starts
when the ExTrig signal rises. If the camera is set for falling edge triggering, exposure starts when
the ExTrig signal falls. Figure 3-4 illustrates programmable exposure with the camera set for rising
edge triggering.
Figure 3-4: Programmable Exposure with Rising Edge Triggering
1
ExTrig period in seconds
------------------------------------------------------------------ frame rate =
1
0.110 s
------------------- 9.1 fps =