Glossary

impedance

1.

The electrical characteristic of a circuit expressed in ohms and/or

 

 

capacitance/inductance.

 

2.

Resistance.

in.

Inch or inches.

instrument driver

A set of high-level software functions that controls a specific GPIB, VXI,

 

or RS232 programmable instrument or a specific plug-in DAQ device.

 

Instrument drivers are available in several forms, ranging from a function

 

callable language to a virtual instrument (VI) in LabVIEW.

instrumentation

A circuit whose output voltage with respect to ground is proportional to the

amplifier

difference between the voltages at its two inputs. An instrumentation

 

amplifier normally has high-impedance differential inputs and high

 

common-mode rejection.

interchannel delay

Amount of time that passes between sampling consecutive channels in an

 

AI scan list. The interchannel delay must be short enough to allow sampling

 

of all the channels in the channel list, within the sample interval. The

 

greater the interchannel delay, the more time the PGIA is allowed to settle

 

before the next channel is sampled. The interchannel delay is regulated by

 

ai/ConvertClock.

interface

Connection between one or more of the following: hardware, software, and

 

the user. For example, hardware interfaces connect two other pieces of

 

hardware.

interrupt, interrupt

1.

A means for a device to notify another device that an event occurred.

request line

2. A computer signal indicating that the CPU should suspend its current

 

 

 

task to service a designated activity.

IOH

Current, output high.

IOL

Current, output low.

IRQ

See interrupt, interrupt request line.

K

kHz

Kilohertz—A unit of frequency; 1 kHz = 103 = 1,000 Hz.

kS

1,000 samples.