![National Instruments NI PCIe-8255R Скачать руководство пользователя страница 10](http://html.mh-extra.com/html/national-instruments/ni-pcie-8255r/ni-pcie-8255r_user-manual_709980010.webp)
Chapter 1
Introduction
©
National Instruments Corporation
1-3
This Builder file provides a guide you can use for developing applications
in any ADE, such as LabWindows
™
/CVI
™
or Visual Basic, using the
Vision Assistant machine vision and image processing libraries. Using the
LabVIEW VI creation wizard, Vision Assistant can create LabVIEW VI
diagrams that perform the prototype you created in Vision Assistant.
You can then use LabVIEW to add functionality to the generated VI.
IEEE 1394 and the NI 8255R
The NI 8255R uses FireWire
®
(IEEE 1394) technology. FireWire is a
cross-platform implementation of the high-speed serial data bus—defined
by the IEEE 1394-1995, IEEE 1394a-2000, and IEEE 1394b-2002
standards—that can move large amounts of data between computers and
peripheral devices. It features simplified cabling using twisted pairs, hot
swapping, and transfer speeds of up to 800 megabits per second. You can
support up to 63 devices on the high-speed bus with IEEE 1394.
The NI 8255R provides two direct-connect IEEE 1394b bilingual ports,
which support IEEE 1394a and IEEE 1394b devices
1
. More IEEE 1394
devices can be added using IEEE 1394 hubs. The NI 8255R can acquire
images from IEEE 1394 cameras conforming to the
IIDC 1394-based
Digital Camera Specification, Version 1.30
and later.
The IEEE 1394 bus provides a fixed amount of bandwidth that is shared
between the two IEEE 1394 ports on the NI 8255R. These ports provide
direct connection for up to two DCAM-compliant IEEE 1394 cameras,
depending on the amount of bandwidth each camera requires. Higher frame
rates and larger image sizes require a higher data transfer rate and use more
bandwidth.
Functional Overview
The NI 8255R features a high-speed data path optimized for receiving and
formatting video data from IEEE 1394 cameras.
1
Using an IEEE 1394a device with the NI 8255R requires a 1394a-to-1394b cable or adapter.