9 Basic Parameters and Commands
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9
Basic Parameters and Commands
This section illustrates the basic configuration options and general commands available for the user,
being important for the operation of an ex factory preconfigured camera. Most probably the
information stated here will be sufficient for most of the users. In case that nevertheless a more
extensive configuration of the correction modules should become necessary, one may refer to the
detailed description of the correction module parameters within section 10
9.1
Select a Correction Data Set (
S
)
In the case that the IRC-320 is equipped with multiple correction data sets for different operation
conditions the image quality can be improved by activating another correction data set if the
environmental conditions have changed.
For a quick access to the (optionally available) different correction data sets, the correction data
memory is subdivided into 32 single pages. Each of these pages can store a complete set of correction
data (parameters
A
and
B
)
. At all times only one page can be active simultaneously and all eventual
modification of the correction data takes place within this page. For each correction memory page a
further pair of registers for the parameters
J
and
K
is available. In order to enable an access on the
values
J
and
K
of each correction data set, the page address also serves as access address to the
register pairs.
The memory pages are filled with data starting at the address “0”. The highest valid address depends
on the number of correction data sets stored in the camera, however it can not exceed 31 (0x1F). If e.g.
27 correction data sets are available this would result in a maximum valid page address of 0x1A.
Both parameters,
A
and
B
together, affect the choice and the number of data sets to be loaded.
By means of the parameter
S
the address of the active page can be adjusted:
Example:
Activate the eleventh correction data set (address 10 = 0xA).
>
S=A[CR]
9.2
Automatic Calibration (
k
)
Beside the manual selection of data sets with parameter
S
also an automatic calibration (one-time or
timer controlled repeating) can be carried out. The automatic process tries to determine the best data
set
S
(if several available) and activates it. The IRC-320 variants additional employ the
electromechanical shutter to acquire a temporary background correction image.
Criterion for the data set selection is a statistics value which is correlating with the fixed pattern noise,
being visible within the image. For the determination of this statistics value an image is recorded and
stored by means of the first “Integrator / Image Memory” module in the chain. This acquired image is
tested in succession with each correction set being available in the memory by determining the
statistics value of the corrected data. Finally that memory page
S
becomes activated, which is showing
the best results for the statistics value.
Depending on the number of available data sets the automatic data set selection can take some
seconds. During the data set selection the image output is stopped by suppression of the FVAL signal.
According to each image content, at the same conditions diverse correction sets can be chosen in case
they are quite similar to each other. But generally the data set which is optimum for the actual image
content becomes activated.
Avoid triggering the camera while the calibration is in progress. Depending on the camera model and
current
j
parameter configuration, the actions accomplished by the
k
command and its output at the
serial interface may vary. Refer to the corresponding command reference in appendix 11.1 for details.
VDS Vosskühler GmbH
IRC-320
