Print
PDFOverview
FireWire, also known as IEEE 1394 or i.Link, is a high-performance serial bus originally developed by Apple Computer in the 1989. The baseline specification handles throughput rates of 100 megabits per second (Mbits/s), 200 Mbits/s, and 400 Mbits/s. The IEEE 1394 Trade Association has revised the specification to increase this transfer rate to 3.2 gigabits per second (Gbits/s). FireWire also features hot-pluggable technology that enables devices to be connected and disconnected while the system is powered up. In addition, devices operating at different communication rates can exist on the same communications chain.
Table of Contents
How can the IEEE 1394 (FireWire) bus be used for computer-based measurement and automation?
Currently, Microsoft handles FireWire in Windows Vista/XP/2000/Me/98 natively. National Instruments offers several data acquisition (DAQ) and machine vision products for FireWire:
- Many camera vendors, offer cameras that you can connect to the computer using an IEEE 1394 (FireWire) interface. NI provides NI-IMAQdx software that allows you to easily configure these cameras, acquire images from them, and create applications in LabVIEW that use them. NI-IMAQdx is part of NI Vision Acquisition software.
- The DAQPad-6070E and DAQPad-6052E are E Series DAQ devices for IEEE 1394 (FireWire) that feature plug-and-play configuration and throughput rates up to 1.25 MS/s. Note: Neither of these two products are supported by the NI-DAQmx driver, meaning they are not supported by the Windows Vista operating system.
How is FireWire impacting computer-based measurement and automation?
The FireWire bus embodies several characteristics that make it easier to use than some of the traditional internal PC buses such as PCI and ISA. Devices that connect using FireWire are hot-pluggable, so they eliminate the need to shut down the PC to add or remove a device. The buses also have automatic device detection, meaning that the user does not have to manually configure the device once it is plugged in. The software should detect and install the device on its own.
For applications that require many devices, broadcast mode can be used to synchronize multiple devices with an event or signal. Broadcast mode can also prove useful in an emergency shutdown situation for embedded machine and automation applications. FireWire can deliver synchronized broadcasts from any device to all other devices when operated in broadcast mode.
High-speed data and control applications benefit from the ability of FireWire to deliver data through either isochronous or asynchronous data transfers. With isochronous transfers, the bus guarantees bandwidth with time-based delivery of data packets. Isochronous transport guarantees that a transmission is completed within a given amount of time, but it does not guarantee that the transmission is received error-free. The 1394 protocol guarantees devices that have requested isochronous bandwidth a predetermined number of data packets in each frame. Data-intensive machine vision and DAQ applications often demand this type of guaranteed bandwidth.
On the other hand, measurement and control systems commonly require the ability to respond to events. USB and FireWire allow any device to generate an asynchronous event. Asynchronous transport guarantees accurate delivery, and devices with urgent messages can be given priority over all other devices. Applications for asynchronous transport include delivering control messages and changing device parameters.
How can you take advantage of this technology?
NI offers several products based on the FireWire technology. Please visit the links below for more information about how these products can help you to create measurement and control applications more quickly, as well as more information about this technology.
Related Links:
Products & Services: NI DAQPad-6070E
Products & Services: NI DAQPad-6052E
Products & Services: Vision Acquisition Software
NI Developer Zone: Acquiring from Firewire Cameras with National Instruments NI-IMAQdx and Legacy NI-IMAQ for IEEE 1394
NI Developer Zone: 1394-A or 1394-B
FireWire is a trademark of Apple, Inc., registered in the U.S. and other countries.
Reader Comments | Submit a comment »
Legal
This tutorial (this "tutorial") was developed by National Instruments ("NI"). Although technical support of this tutorial may be made available by National Instruments, the content in this tutorial may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this content with each new revision of related products and drivers. THIS TUTORIAL IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).