NI LabVIEW, PACs Deliver Advanced Machine Control, Reliability
November 8, 2004
When selecting a platform for embedded machine control, the most important decision users make often is not hardware-it is software. With a productive software package, users can quickly build the first prototype and iterate on future design changes. Many machine builders use National Instruments LabVIEW to design their control and measurement systems because it provides both a powerful programming language and a graphical interface for programming and HMI. Machine builders who use NI LabVIEW have always had the choice of Windows-, Macintosh-, and Linux-based platforms; however, many applications now require the reliability of a real-time operating system.
National Instruments programmable automation controller (PAC) platforms, based on the LabVIEW Real-Time and LabVIEW FPGA, use real-time operating systems and control on a chip. These systems are designed for applications requiring the combination of fast design iteration and advanced control, test, and reliability. With LabVIEW, users can select from four National Instruments PACs:
PXI improves on an industrial PC with a real-time OS, standards for cooling, optional non-spinning solid-state hard drives, and intermodule synchronization. The PXI standard requires all chassis to provide air flow for 25W of cooling per module slot, which ensures operation without overheating or shortened life even when using high-power relay or high-speed PXI, or CompactPCI cards.
Compact FieldPoint uses industrially rated parts to achieve high shock and vibration, handle a wide temperature range from -40 to 70C, and achieve Class 1 Division II and Lloyds certifications. It also uses conductive cooling to increase reliability by eliminating moving parts, and it incorporates PC functionality by using a floating-point processor running a real-time OS, Compact Flash drives for data logging, and an Ethernet port for communications.
Compact Vision System (CVS) is a rugged controller designed specifically for machine vision applications. It uses IEEE Standard 1394 FireWire interfaces to communicate with up to 16 cameras in a vision application and run a high-speed Intel processor for fast image analysis. The Compact Vision System platform also uses no moving parts and conductive cooling, so users can mount the system close to the machine.
CompactRIO is a new platform based on LabVIEW FPGA and LabVIEW Real-Time technology. The CompactRIO system uses an FPGA chip with up to 3 million gates to control modular digital and analog I/O. The FPGA chip can run embedded code in silicon for digital control loops up to 1 MHz and analog loops up to 150 kHz. The FPGA can pass information back to a floating-point processor running LabVIEW Real-Time for advanced computation, data logging, and communication.
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