Glossary

NI-DAQ Measurement & Automation Explorer

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Glossary

A
address Character code that identifies a specific location (or series of locations) in memory.

B
base address A memory address that serves as the starting address for programmable registers. All other addresses are located by adding to the base address.
BIOS Basic Input/Output System—BIOS functions are the fundamental level of any PC or compatible computer. BIOS functions embody the basic operations needed for successful use of the computer hardware resources.
bus The group of conductors that interconnect individual circuitry in a computer. Typically, a bus is the expansion vehicle to which I/O or other devices are connected. Examples of PC buses are the ISA and PCI bus.

C
channel
  1. Physical—A terminal where an analog or digital signal may be input or output. A single physical channel can imply more than one terminal as in the case of a differential analog input channel or a digital port of eight lines.
  2. Virtual—A collection of property settings that includes a physical channel, type of measurement or generation, and scaling information.
configuration tree Refers to the left window in Measurement & Automation Explorer, which contains items such as Data Neighborhood and Devices and Interfaces.

D
DAQ
  1. Data AcQuisition.
  2. Collecting and measuring electrical signals from sensors, transducers, and test probes or fixtures and inputting them to a computer for processing.
  3. Collecting and measuring the same kinds of electrical signals with A/D and/or DIO devices plugged into a computer, and possibly generating control signals with D/A and/or DIO devices in the same computer.
device
  1. An instrument or controller that can be addressed as a single entity and controls or monitors real-world I/O points. A device often is connected to the host computer through some type of communication network, or can be a plug-in device.
  2. DAQ. A plug-in data acquisition device, card, or pad that can contain multiple channels and conversion devices. Plug-in devices and PCMCIA cards are all examples of DAQ devices. SCXI modules are distinct from DAQ devices.
DIO digital input/output
driver Software that controls a specific hardware device such as a DAQ device.
drop-down listbox A graphical box with a down arrow button that lets you select values or options from a list. To select a value or option in the selection box, click the down arrow for a complete list of values or options, then use your arrow keys or mouse to select a value or option from the list.

G
gain The factor by which a signal is amplified, sometimes expressed in decibels (dB).

H
hardware The physical components of a computer system, such as the circuit boards, plug-in boards, chassis, enclosures, peripherals, and cables.
hex Hexadecimal; a base-16 numbering system.

I
interrupt A computer signal indicating that the CPU should suspend its current task to service a designated activity.
interrupt level The relative priority at which a device can interrupt.
I/O input/output—the transfer of data to/from a computer system involving communications channels, operator interface devices, and/or data acquisition and control interfaces.
IRQ Interrupt ReQuest
ISA industry standard architecture. Also refers to a common PC expansion bus.

M
MAX Measurement & Automation Explorer.
multiplexed mode An SCXI operating mode in which analog input channels are multiplexed into one module output so that the cabled DAQ device has access to the multiplexed output as well as the outputs on all other multiplexed modules in the chassis through the SCXI bus. Also called serial mode.

N
NI-DAQ National Instruments driver software for DAQ hardware.

O
OLE object linking and embedding
OPC OLE for process control.
operating system Base-level software that controls a computer, runs programs, interacts with users, and communicates with installed hardware or peripheral devices. Also referred to as OS.

P
PCI Peripheral Component Interconnect—a high-performance expansion bus architecture originally developed by Intel to replace ISA and EISA. PCI offers a theoretical maximum transfer rate of 132 Mbytes/s.
PCMCIA An expansion bus architecture that has found widespread acceptance as a de facto standard in notebook-size computers. PCMCIA originated as a specification for add-on memory cards written by the Personal Computer Memory Card International Association.
Plug and Play devices Devices that do not require DIP switches or jumpers to configure resources on the devices. Also called switchless devices.

R
RDA remote device access—A protocol used in NI-DAQ to transparently establish communication, configure, and acquire data on the remote device over a local area network or the Internet.
RT Real-Time—a property of an event or system in which data is processed as it is acquired instead of being accumulated and processed at a later time.
RT Series Processor-based DAQ devices for use with the LabVIEW Real-Time module.

S
SCXI Signal Conditioning eXtensions for Instrumentation—the National Instruments product line for conditioning low-level signals within an external chassis near sensors so only high-level signals are sent to DAQ devices in the noisy PC environment.
sensor A device that responds to a physical stimulus (heat, light, sound, pressure, motion, flow, and so on), and produces a corresponding electrical signal.

T
task A channel or group of channels with the same timing and triggering.
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