Phytec eGrabber-4plus, Hardware Manual

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eGrabber-4plus
174 
PHYTEC Meßtechnik GmbH 2004 L-608e_4
5.3.4 Program Example D OS
In this section a simple program is described running under DOS, to
store an image in the main memory.
For a simple example we restrict us to a constant format of the image
and digitize a single shot. The format of the image is 256 x 256 pixels.
We assume, that only one eGrabber-4plus is installed in the computer.
If more grabbers are installed, only the first Grabber is used.
At first an object „
Grabber
“ is created which provides the interface to
the eGrabber-4plus. The image should be stored in an array designated
with
pEWert
. At this point it is necessary to determine the multitude
of data for the required image. The dimension of the image is 256 x
256 pixels, and should be stored as RGB-color picture, using the
RGB24-format. RGB24 requires 3 Byte per pixel. So we need
256
.
256
.
3 Byte for one image.
The operation of the Grabber starts with the identification, to check if
a Grabber is available. Max_Device_Number() delivers the number
of Grabber boards installed in the system. If the number = 0, no
Grabber board is available in the computer, and the program will be
cancelled prematurely.
If one or several Grabber cards are found, the Grabber will be initial-
ized with the function call Initialize(1). The parameter 1 indicates that
the first Grabber should be initialized. If several Grabber boards are
available the function Initialize() must be executed for all Grabber
cards.
It makes sense to check after each call with Get_Error() if any errors
occurred and if the instruction was successful. In order to keep the
general view, this is not done in this example.