National Instruments NI VISION PCI-8254R 用户手册
Chapter 1
Introduction
1-4
ni.com
Figure 1-1. NI 8254R Block Diagram
Start Conditions
The NI 8254R can start acquisitions in the following ways:
•
Software control—The NI 8254R supports software control of
acquisition start. You can configure the NI 8254R to capture a fixed
number of frames. Use this configuration for capturing a single frame
or a sequence of frames.
acquisition start. You can configure the NI 8254R to capture a fixed
number of frames. Use this configuration for capturing a single frame
or a sequence of frames.
•
Trigger control—You can start an acquisition by enabling external
trigger lines. Each of these inputs can start a video acquisition on a
rising or falling edge.
trigger lines. Each of these inputs can start a video acquisition on a
rising or falling edge.
Acquisition Window Control
You can configure the following parameter on the NI 8254R to control the
video acquisition window:
video acquisition window:
•
Acquisition window—The NI 8254R and the IIDC 1394-based
Digital Camera Specification allow you to specify a particular region
of active pixels and lines on a camera to acquire. In many cases,
specifying a smaller acquisition window will increase the maximum
frame rate of the camera. Valid acquisition windows, and their
corresponding frame rates, are defined by the camera.
Digital Camera Specification allow you to specify a particular region
of active pixels and lines on a camera to acquire. In many cases,
specifying a smaller acquisition window will increase the maximum
frame rate of the camera. Valid acquisition windows, and their
corresponding frame rates, are defined by the camera.
ISO Out
ISO Power
Connection
1394
Power Conn
Power
Supply
+5 V, +1.5 V
TTL Out
CPLD
Dust
MITE
MITE
V2 FPGA
DSUB
TTL In
ISO In
Config ROM
PCI
Bridge
PCI
CONN
1394A
Controller
1394
Conns