Basler A640F, User Manual

Page: 170 / 188

Smart Features
6-34
BASLER A640
f
DRAFT
6.7.13 Shutter Time Base
As described in Section 3.2.1 , exposure time is determined by a combination of two values. The
first is the setting in the Value field of the Shutter control register (see page 4-30 ). The second is
the Shutter Time Base. Exposure time is determined by the product of these two values:
Exposure Time = (Shutter Value Setting) x (Shutter Time Base)
The shutter time base is fixed at 20 µs by default and the exposure time is normally adjusted by
changing the setting in the Value field of the Shutter control register. However, if you require an
exposure time that is shorter or longer than what you can achieve by changing the shutter value
alone, the Shutter Time Base CSR can be used to change the shutter time base.
To change the shutter time base:
• Set the Enable field in the Shutter Time Base CSR to 1
• Set the Time Base field to your desired time base value
Example
Assume that you have set the Value field of the Shutter control register to 325. Also assume that
you have enabled the time base smart feature and that you have set the Time Base field in the
Shutter Time Base CSR to 0.000150 second. In this case:
Exposure Time = (Shutter Value Setting) x (Shutter Time Base)
Exposure Time = (325) x (0.000150 s)
Exposure Time = 0.048750 s
L
The shutter time base smart feature does not add information to the image data
stream and can be accessed even when the extended data stream feature (see Sec-
tion
6.7.1 ) is disabled.
The shutter time base smart feature can be enabled regardless of the video format.