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Why PCI for Data Acquisition?
Data Translation manufactures a wide range of data acquisition hardware for use on the high-performance PCI (Peripheral Component Interconnect) bus. This includes boards like the DT3010 Series, DT3001 Series, and DT301 Series. By taking advantage of the PCI bus, these plug-in boards offer convenient and affordable high-performance solutions for demanding data acquisition applications.
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What Is the PCI Bus?
The PCI bus is an integral part of today's high-performance personal computer systems. Conceived and designed as a way to give peripheral components high-bandwidth access to the host processor in a PC, the PCI bus is a board-level expansion standard with important benefits to anyone whose work involves PC-based data acquisition. In replacing the aging 3 to 5 MB/s ISA (Industry Standard Architecture) expansion bus, the PCI bus breaks open the bandwidth bottleneck by providing a 132 MB/s (theoretical), 95 MB (typical) burst-rate highway. In addition to its high bandwidth, the PCI bus features master/slave operation to reduce latency and offload the host CPU. Other advantages include plug-and-play autoconfiguration to simplify installation; processor and platform independence, which lets designers easily develop PCI peripherals to run on other platforms than the Pentium PC; and a specified migration path to 3.3 V, which simplifies the design of portable systems.
Benefits of PCI for Data Acquisition Applications
For data acquisition, the high-bandwidth of the PCI bus allows simultaneous, realtime gathering of gap-free analog and digital input data, along with outputs for analog stimuli and digital control. Data acquisition boards built for the PCI bus can feed acquired data directly to the PC's memory, minimizing the need for onboard memory. Unlike ISA boards, which run the risk of overflowing data because they need a large onboard memory buffer, PCI data acquisition boards do not leave gaps in the acquired data. In other words, PCI boards do not lose data like ISA boards can if the bus does not respond fast enough to the board's request to transfer data. High bandwidth also ensures gap-free data transfer by allowing several subsystems to be active simultaneously rather than sequentially. For example, Data Translation's DT3010 and DT3000 Series PCIbased boards feature continuous performance, which provides gap-free simultaneous A/D, D/A, and digital I/O operation at full-rated throughput. To do this, the boards have circular buffers that store multiple values that are transferred across the PCI bus simultaneously to take advantage of the high bandwidth. The DT3010 board features an A/D throughput of 1.25 Msamples/s from one channel, up to 32 analog inputs, two analog outputs, up to 16 digital I/O lines, and four user counter/timers. The DT3003 board features an A/D throughput of 330 kHz from one channel, up to 64 analog inputs, two analog outputs, and eight digital I/O lines.
Because boards on the PCI bus can transfer without intervention from the host CPU, data can be simultaneously acquired and processed in real time. For example, as data is sampled, the host CPU can perform a mathematical operation, plugging the results into a spreadsheet for analysis. Moreover, by adding digital I/O functions, you can set up real-time collection and control experiments that would be impossible to conduct across the ISA bus. For example, a data acquisition system running on the ISA bus would run out of bandwidth carrying just two analog outputs and one analog input, each running at 200 kSamples/s. Plus, due to the plug-and-play feature of the PCI bus, system resources are all configured automatically. No jumpers or DIP switch settings are required. Check out all of our high-performance, low-cost, and convenient PC-based data acquisition boards for the PCI bus.
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