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1:35 PM
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4-Channel Monochrome Image Acquisition
4-Channel Monochrome Image Acquisition
Quick and Easy Camera Configuration
You can easily configure standard and nonstandard video capture
with NI Measurement & Automation Explorer, delivered with
NI-IMAQ. This utility is an interactive tool for setting the camera
type (RS-170, CCIR, NTSC, and PAL), programmable ROI, aspect
ratio, and antichrominance filter. Use this interactive utility to set
up acquisition from noninterlaced progressive-scan cameras and
to create your own camera configurations for nonstandard video.
Use the external lock feature to set variable-scan acquisition for
microscopes and other sources that generate their own pixel
clock and horizontal and vertical synchronization signals.
DAQ Synchronization
The RTSI bus or PXI trigger bus provide a flexible synchronization
scheme between any National Instruments IMAQ, DAQ, or
motion device and your PCI-1409 or PXI-1409, respectively.
Trigger Control and Mapping Circuitry
The trigger control and mapping circuitry routes, monitors, and
drives the external and RTSI or PXI trigger bus lines. You can
configure each of these lines to start or stop acquisition on a rising
or falling edge, or use each line as digital I/O. You can also map
the lines to onboard status values (CSYNC, Acquisition in
Progress, and Acquisition Complete).
Image Acquisition Performance Gains
with Partial Image Scanning
For improved throughput and processing bandwidth, the
acquisition and ROI control circuitry monitors the incoming video
signal and routes the active pixels to the FIFO. In addition to being
able to digitize an entire frame, an NI 1409 can perform pixel and
line scaling (decimation) and ROI acquisition. With pixel and line
scaling, multiples (2,4,8) of pixels and/or lines can be transferred
to the PCI bus. Using ROI acquisition, you select an area in the
acquisition window that will be transferred to the PCI bus.
Antichrominance and Lowpass Filter
NI 1409 devices have an antichrominance filter, which can remove
chrominance information from a color video signal. There are two
software selectable antichrominance filters – one for NTSC color
-coded signals (a 3.58 MHz notch filter), and another for PAL color
-coded signals (a 4.43 MHz notch filter). Use the lowpass filter at
9 MHz to remove unwanted noise.
10-Bit A/D and Look-Up Table (LUT)
An A/D converter performs the image digitization, the result of
which passes to a 1,024 by 10 RAM LUT. You can configure the
LUT to implement simple imaging operations, such as gamma
manipulation, contrast enhancement, data inversion, or any
nonlinear transfer function.
Hardware
PCI Interface
The PCI bus is the electrical interface for both NI PCI-1409 and
NI PXI-1409. The PCI interface, implemented with the National
Instruments MITE ASIC, can transfer data at a maximum
sustained rate of 100 Mbytes/s in master mode to maximize the
use of the available bandwidth. The interface logic ensures that
the NI 1409 meets the loading, driving, and timing requirements
of the PCI specification.
Vision
Programmable Gain and Offset
The NI 1409 has programmable gain and offset circuitry for
optimizing the input signal range.
VCR Circuitry
Scatter-Gather DMA Controllers
An NI 1409 has three independent onboard DMA controllers. The
DMA controllers can transfer data between the Host memory and
the onboard FIFO via the PCI bus. Each of these controllers
performs scatter-gather DMA, which means the DMA controller
can reconfigure on the fly, and thus perform continuous image
transfers to either contiguous or fragmented buffers.
Because many commercial and home VCRs have noisy
synchronization signals or no synchronization at all, VCRs are
difficult to use with most image acquisition hardware. However,
with its built-in circuitry and logic for handling video signals from
VCRs, the NI 1409 can acquire monochrome images from VCRs.
Digital I/O
The NI 1409 Series includes four general-purpose digital
input/output lines for general-purpose triggering and pulse
generation capabilities. In addition, each NI 1409 includes four
digital output lines for lighting, shutter, camera control, and
pulse generation.
Onboard Memory
An NI 1409 has 16 MB of onboard memory used to temporarily
store the image being transferred to the PCI bus. With 16 MB,
you can buffer large images during image acquisition.
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