"Let's go ahead and apply CASE tools and UML to designing the PCI interface using that new XML standard."
Admit it, how many times has someone mentioned an acronym in a technical discussion and everyone pretends to understand because nobody wants to ask what it stands for and look ignorant? Well, here's your chance to see what all the acronyms in this chapter stand for and where they came from. Use this list to put your colleagues to the test!
AC: Alternating Current. This acronym originally referred to how a device was powered, with AC being the plug in the wall and DC (direct current) being batteries. Now it's used more generally to refer to any kind of signal (not just current) that varies "rapidly" (whatever you want that to mean) with time.
AC/DC: A rockin' Aussie band. (Rock historians will note that the band was founded by two Scottish brothers, Angus and Malcom Young, who immigrated to Australia ten years prior to forming the band.)
ADC: or A/D Analog-to-Digital Conversion. This conversion takes a real-world analog signal, and converts it to a digital form (as a series of bits) that the computer can understand. Many times the chip used to perform this operation is called "the ADC."
DAQ: Data AcQuisition. This little phrase just refers to collecting data in general, usually by performing an A/D conversion. Its meaning is sometimes expanded to include, as in this book, data generation. Don't confuse DAQ and DAC, which sound the same when pronounced in English. (DAC, or D/A, stands for Digital-to-Analog Conversion, usually referring to the chip that does this.)
DC: Direct Current. The opposite of AC. No longer refers to current specifically. Sometimes people use DC to mean a constant signal of zero frequency. In other cases, such as in DAQ terminology, DC also refers to a very low-frequency signal, such as something that varies less than once a second.
DMA: Direct Memory Access. You can use plug-in DAQ devices that have built-in DMA, or buy a separate DMA board. DMA lets you throw the data you're acquiring directly into the computer's RAM (there we go, another acronym), thus increasing data transfer speed. Without DMA, you still acquire data into memory, but it takes more steps and more time because the software has to direct it there.
IEEE: Institute of Electrical and Electronics Engineers. An international non-profit, professional association for the advancement of technology. IEEE sets standards in a variety of industries. For example, in this chapter, we will learn about TEDS, and in Chapter 14, "Advanced LabVIEW Data Concepts," we will learn about GPIB and Ethernetall of which are IEEE standards.
MAX: Measurement & Automation Explorer software from National Instruments. Your one-stop-shop for setting up and testing your National Instruments DAQ hardware and software, and your external instruments (on Windows platforms only).
MXI-3: Multisystem eXtension Interface (version 3) is a high-speed serial interface bus for bridging PCI buses. For example, it allows you to chain multiple PXI chassis together and allows a single computer to control the cards on all the chassis.
NI-DAQmx: NI-DAQmx is the latest DAQ driver from National Instruments. It supersedes Traditional NI-DAQ, the previous DAQ driver.
PXI: PCI eXtensions for Instrumentation. PCI ("Peripheral Component Interconnect") is a standard bus, used on most computers for plugging in dedicated device cards. PXI refers to an open hardware architecture, embraced by National Instruments, for integrating high-performance, modular components for data acquisition, instrument control, image processing, and more.
RTSI: Real-Time System Integration bus. The National Instruments timing bus that connects DAQ, Motion, Vision, and other devices directly for precise synchronization of functions.
SCC: Signal Conditioning Carriers. A compact, modular form factor for signal conditioning modules (for example, optically-isolated relays), sold by National Instruments.
SCXI: Signal Conditioning eXtensions for Instrumentation. A high-performance signal conditioning system devised by National Instruments, using an external chassis that contains I/O modules for signal conditioning, multiplexing, and so on. The chassis is wired into a DAQ device in the PC.
SISTA: Sometimes I'm Sick of These Acronyms. Just kidding.
TEDS: Transducer Electronic Data Sheets. An IEEE standard (Institute of Electrical and Electronic Engineers standard 488.2) for smart sensors that store their own calibration data.
TLA: Three-Letter Acronym. Not to be confused with FLA (Four-Letter Acronym), which is, ironically, a TLA!
USB: Universal Serial Bus, a standard bus on most PCs for connecting external peripherals.
VXI: Talk about acronym abuse; this is an acronym for an acronym: VME eXtensions for Instrumentation. VME stands for Versa-Modular Eurocard. VXI is a very high-performance system for instrumentation. You can buy VXI instruments that are small modules (instead of the regular big instrument with a front panel) that plug into a VXI chassis. The VXI chassis often has an embedded computer motherboard, so you don't have to use an external PC. VXI is an open industry standard, which means that companies besides National Instruments support it.
