Basler Vision Technologies Sprint Series, Руководство пользователя

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Exposure Start and Exposure Time Control
Basler sprint Mono Cameras 69
4.1.2 Selecting an ExSync Exposure Mode & Setting
the Exposure Time
You can select an ExSync exposure time control mode and set the exposure time for the ExSync
programmable mode with the Camera Configuration Tool Plus (CCT+) or by using binary write
commands from within your own application to set the camera’s control and status registers
(CSRs).
With the CCT+
With the CCT+ (see Section 7.1 on page 156 ), you use the Exposure Time Control Mode parameter
in the Exposure parameters group to select the ExSync edge controlled, ExSync level controlled or
ExSync programmable exposure time control mode. If you select the ExSync programmable mode,
you can use the Exposure Time parameter to set the exposure time.
By Setting CSRs
You select the exposure time control mode by writing the appropriate value to the Mode field of the
Exposure Time Control Mode CSR (see
page 168 ).
If you select the ExSync programmable mode, you will also need to set the exposure time. You set
the exposure time by writing a value to the Absolute Exposure Time field or to the Raw Exposure
Time field of the Exposure Time CSR (see
page 169 ).
Section 7.2.2 on page 164 explains CSRs and the difference between using the “absolute” field and
the “raw” field in a CSR. Section 7.3.1 on page 197 explains using read/write commands.
4.1.3 Guidelines When Using an ExSync Signal
When using an ExSync signal to control exposure, several general guidelines must be followed:
„
The ExSync signal must toggle.
„
In order for the camera to detect a transition from low to high, the ExSync signal must be held
high for at least 2.0 µs when the camera is set for the level controlled exposure mode and for
at least 100 ns when the camera is set for programmable or edge controlled exposure mode.
„
The ExSync signal must be held low for at least 2.0 µs.
„
In ExSync edge controlled mode:
The actual exposure time = line period - 1.8 µs (± 25 ns).
„
In the ExSync programmable mode:
The maximum allowed programmed exposure time = line period - 1.3 µs (± 25 ns).
(If you set the exposure time to be longer than this allowed maximum, the camera will behave
as if it is in ExSync edge controlled mode.)