National-instruments Data Acquisition Device NI USB-621x Manual de usuario descargar pdf (Pagina 170)

Glossary

NI USB-621x User Manual G-12 ni.com

PFI Programmable Function Interface.

PGIA Programmable Gain Instrumentation Amplifier.

physical channel See channel.

posttriggering The technique used on a DAQ device to acquire a programmed number of

samples after trigger conditions are met.

power source An instrument that provides one or more sources of AC or DC power. Also

known as power supply.

ppm Parts per million.

pretriggering The technique used on a DAQ device to keep a continuous buffer filled with

data, so that when the trigger conditions are met, the sample includes the

data leading up to the trigger condition.

pulse A signal whose amplitude deviates from zero for a short period of time.

pulse width The time from the rising to the falling slope of a pulse (at 50% amplitude).

quadrature encoder An encoding technique for a rotating device where two tracks of

information are placed on the device, with the signals on the tracks offset

by 90° from each other. This makes it possible to detect the direction of the

motion.

range The maximum and minimum parameters between which a sensor,

instrument, or device operates with a specified set of characteristics. This

may be a voltage range or a frequency range.

real time 1. Displays as it comes in; no delays.

2. A property of an event or system in which data is processed and acted

upon as it is acquired instead of being accumulated and processed at a

later time.

3. Pertaining to the performance of a computation during the actual

time that the related physical process transpires so results of the

computation can be used in guiding the physical process.

1 2 ... 165 166 167 168 169 170 171 172 173 174 175 ... 184 185

Sin comentarios

National-instruments Data Acquisition Device NI USB-621x Manual de usuario Pagina 170