Glossary

cascading

Process of extending the counting range of a counter chip by connecting to

 

the next higher counter.

CE

European emissions control standard.

channel

Pin or wire lead to which you apply or from which you read the analog or

 

digital signal. Analog signals can be single-ended or differential. For digital

 

signals, you group channels to form ports. Ports usually consist of either

 

four or eight digital channels.

clock

Hardware component that controls timing for reading from or writing to

 

groups.

CMOS

Complementary metal-oxide semiconductor.

CMRR

Common-mode rejection ratio—A measure of the ability of a differential

 

amplifier to reject interference from a common-mode signal, usually

 

expressed in decibels (dB).

common-mode rejection

The ability of an electronic system to cancel any electronic noise pick-up

 

that is common to both the positive and negative polarities of the input leads

 

to the instrument front end. Common mode rejection is only a relevant

 

specification for systems having a balanced or differential input.

common-mode signal

1. Any voltage present at the instrumentation amplifier inputs with

 

respect to amplifier ground.

 

2. The signal, relative to the instrument chassis or computer’s ground, of

 

the signals from a differential input. This is often a noise signal, such

 

as 50 or 60 Hz hum.

connector

1. A device that provides electrical connection.

 

2. A fixture (either male or female) attached to a cable or chassis for

 

quickly making and breaking one or more circuits. A symbol that

 

connects points on a flowchart.

convert rate

Reciprocal of the interchannel delay.

count

The number of events, such as zero crossings, pulses, or cycles.

counter

1. Software. A memory location used to store a count of certain

 

occurrences.

 

2. Hardware. A circuit that counts events. When it refers to an instrument,

 

it refers to a frequency counter.