Basler Vision Technologies A202k, User Manual

Page: 52 / 118

Operation and Features
3-22
BASLER A202
k
DRAFT
3.6 Digital Shift
The “digital shift” feature allows you to change the group of bits that is output from each ADC.
Using the digital shift feature will effectively multiply the output of the camera by 2 times or 4 times.
Section
3.6.1 describes how digital shift works when the camera is operating in 10 bit output mode
and Section 3.6.2 describes how digital shift works when the camera is operating in 8 bit output
mode.
Also note the precautions that you must observe to effectively use this feature (see Section 3.6.3 ).
You can set digital shift using either the Camera Configuration Tool Plus (see Section 4.1 and the
configuration tool’s on-line help) or binary commands (see Section 4.2 ). With the configuration
tool, you use the Digital Shift setting in the Output group to set digital shift. With binary commands,
you use the Digital Shift command.
3.6.1 Digital Shift in 10 bit Output Mode
No Shift
As mentioned in Section 3.1 , the
A202
k
uses 10 bit
ADCs to digitize the output from the CCD sensor.
When the camera is operating in 10 bit output
mode, by default, the camera transmits the 10 bits
that are output from each ADC.
Shift Once
When the camera is set to shift once, the output
from the camera will include bit 8 through bit 0 from
each ADC along with a zero as an LSB.
The result of shifting once is that the output of the
camera is effectively doubled. For example,
assume that the camera is set for no shift, that it is
viewing a uniform white target, and that under these
conditions the reading for the brightest pixel is 100.
If you changed the digital shift setting to shift once,
the reading would increase to 200.
L
Note that if bit 9 is set to 1, all of the other bits will automatically be set to 1. This
means that you should only use the shift once setting when your pixel readings in
10 bit mode with no digital shift are all below 512.
Since the shift once setting requires that the least significant bit always be "0", no
odd gray values can be output. In this case, the gray value scale will only include
gray values of 2, 4, 6 and so forth. The absence of some gray values is commonly
called "Missing Codes”.