Allied Vision Technologies F-131B, Technical Manual, Page: 65 / 183

Description of the data path
8.6 Setting the brightness (black level or offset)
p
-m s (@ 8 bit). Increments are in 1/16 LSB (@ 8 bit).
MOS-model: 0 … +127 (@ 8 bit)
ula ffset
e IIDC register brightness at offset 800h is used for this purpose. Description is identical to
8.7 Auto shutter
In combination with auto white balance, all CCD- and CMOS models are equipped with auto-
shutter feature.
When enabled, the auto shutter adjusts the shutter within the default shutter limits or within
those set in advanced register F1000360h in order to reach the reference brightness set in auto
exposure register. Increasing the auto exposure value increases the average brightness in the
image and vice versa.
The applied algorithm uses a proportional plus integral controller (PI controller) to achieve
minimum delay with zero overshot.
The following table shows the Shutter CSR.
It is ossible to set the black level in the camera within the following ranges:
CD odels: 0...+16 gray value C
C
The form
for gain and offset setting is: Y`= G*Y+O
Setting the gain does not change the offset (black value) for CCD models.
Setting the gain changes the offset (black value) for CMOS models. This is due to the lack
of black clamping circuitry in sensor.
Th
GAIN.
Register Name Field Bit Description
0xF0F0081C SHUTTER Presence_Inq [0] Presence of this
feature: 0: N/A;
1: Available
Abs_Control [1] Absolute value
control
O: Control with value
in the value field
1: Control with value
in the absolute value
CSR
If this bit= 1 the
value in the value
field has to be
ignored
- [2..4] Reserved
One_Push [5] Write: Set Bit high to
start
MARLIN Technical Manual
Page 65