Digital Shift; Digital Shift In 10 Bit Output Mode - Basler A400K User Manual

Basic Operation and Features

3.7 Digital Shift

The "digital shift" feature lets you change the group of bits that is output from the ADC. Using the
digital shift feature will effectively multiply the output of the CMOS sensor by 2 times or 4 times.
Section 3.7.1 describes how digital shift works when the camera is operating in 10 bit output
mode, and Section
output mode.
Before you use digital shift, also observe the precautions described in Section 3.7.3.

3.7.1 Digital Shift in 10 Bit Output Mode

No Shift
As mentioned in Section 3.1, the A400k uses 10 bit
ADCs to digitize the output from the CMOS 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.
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 with no digital
shift are all below 512.
Since the shift once setting requires that the least significant bit (LSB) always be
"0", no odd gray values can be output. 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".
3-20
DRAFT
3.7.2 describes how digital shift works when the camera is operating in 8 bit
Basler A400k