Matrox Matrox Radient eV-CXP, Installation And Hardware Reference, Page: 39 / 70

Acquisition memory 39
When you want to configure auxiliary signals as quadrature input signals, you
must use two signals for each quadrature encoder: one to carry the first bit, and
one to carry the second. You can enable the quadrature decoder, or configure its
settings, using the MIL-Lite function
MdigControl() with
M_ROTARY_ENCODER... , or by modifying the DCF file with Matrox
Intellicam.
The LVDS receivers of the Matrox Radient eV-CXP board support input from
-4 V to +5 V.
❖
Note that an external source must be used to power the rotary encoder (for
example, your computer’s 5 V power source).
Acquisition memory
Matrox Radient eV-CXP has 1, 2, or 4 Gbytes of DDR3 SDRAM acquisition
memory.
This memory is accessed through the memory interface, and is used to
store acquired images. The memory interface transfers data to and from memory
at up to 8.5 Gbytes/sec.
Matrox Radient eV-CXP has 128 Mbytes of memory mapped onto the PCIe bus.
You can use a Host pointer to access this memory, or you can access it directly
from another PCIe bus master; this memory is referred to as shared memory. To
allocate a buffer in shared memory, use the MIL-Lite function
MbufAlloc...() with
M_ON M_SHARED .
Data conversion
The color space converter and image formatter can convert data in the following
ways:
• Subsampling. Image data can be subsampled. This can be useful to implement
custom software-based motion detection because at a reduced scale, image
comparison is faster.
The color space converter and image formatter can subsample in the horizontal
direction by integer factors of 1 to 16; whereas, there is no restriction in the vertical
direction. The color space converter and image formatter uses nearest-neighbor
interpolation.