User`s manual

Basic Operation and Features
Basler A500
k 3-41
PRELIMINARY
3.10.2 Dynamic Area of Interest (A504k, A503k Only)
Dynamic AOI is a useful feature for object tracking applications. It needs to be activated if you
want to displace the AOI position diagonally.
To show the usefulness of this feature, this section explains first what happens if you move the
AOI diagonally with Dynamic AOI deactivated. When you change the AOI starting line register, the
value becomes immediately active. As a result, the AOI shifts vertically in one of the next images.
Since you can only write commands to the camera sequentially, you would enter the AOI starting
column register next. The value becomes active and the AOI shifts horizontally in one of the next
images. Even if the commands are written immediately after one another, the image output is so
fast that the commands will be realized separately in different images. With Dynamic AOI
deactivated, shifting the AOI position diagonally can only be achieved via an intermediate AOI
position.
With Dynamic AOI activated, the AOI shifts diagonally without moving to an intermediate position.
You enter the AOI values as follows:
1. You write the AOI Starting Line register. It does not yet become active.
2. You write the AOI Starting Column register.
Now both values become active in the camera at the same time.
You can activate or deactivate Dynamic AOI using either the Camera Configuration Tool Plus (see
section 4.1) or binary commands (see section 4.2.4.15 ”Area of Interest Stamp and Dynamic Area
of Interest (A504k, A503k Only)”).
3.10.3 Area of Interest Stamp (A504k, A503k Only)
A command sent to the camera will become active only after a short latency. At low frame rates,
the command usually becomes active for the next image. At high frame rates you do not know on
exactly which image the command will become active. This information is especially required for
tracking applications where the camera is operating at a high frame rate and the area of interest
is changed frequently. Information about the selected AOI can be stamped into the image.
If the area of interest stamp feature is activated, the stamp is applied to the last 10 pixels of the
last line, that is, the bottom right of every image. It replaces the image information for these pixels
(1 Byte per pixel). The stamp contains the following information:
Frame Counter: 16 Bit counter. The counter is increased by one with each image and ranges
from 0 to 65535. After 65535, the counter restarts at 0. The counter can not be reset.

AOI Width and AOI Height are not affected by dynamic AOI.
With Dynamic AOI, the AOI can only shift in steps of 10 columns and 10 lines due to
the limitations for choosing AOI starting columns (see section 3.10).
Pixel0
high byte
Pixel1
low byte
Pixel2
high byte
Pixel3
low byte
Pixel4
high byte
Pixel5
low byte
Pixel6
high byte
Pixel7
low byte
Pixel8
high byte
Pixel9
low byte
Frame Counter AOI Starting
Column
AOI Width AOI Starting Line AOI Height
Table 3-3: AOI Stamp Structure