Omega Engineering OMB-DAQTEMP Series 用户手册

G-2

                          

08-23-02

Glossary

A circuit or device that converts digital values (binary bits), into analog signals.

A DIP switch is a group of miniature switches in a small Dual In-line Package (DIP).  Typically,

users set these switches to configure their particular application.

The differential mode measures a voltage between 2 signal lines for a single channel.  (Also see

single-ended mode).

Differential mode voltage refers to a voltage difference between two signals that are referenced to

a common point.  Example: Signal 1 is +5 VDC referenced to common.  Signal 2 is +6 VDC
referenced to common.

If the +5 VDC signal is used as the reference, the differential mode voltage is +1 VDC

(+ 6 VDC - +5 VDC = +1 VDC).

If the +6 VDC signal is used as the reference, the differential mode voltage is -1 VDC

(+ 5 VDC - +6 VDC = -1 VDC).

Electrostatic discharge (ESD) is the transfer of an electrostatic charge between bodies having

different electrostatic potentials. This transfer occurs during direct contact of the bodies, or
when induced by an electrostatic field.  ESD energy can damage an integrated circuit (IC).

Some transducers  [e.g. strain gages, thermistors, and resistance temperature detectors (RTDs)]

require a known voltage or current.  Typically, the variation of this signal through the
transducer corresponds to the condition measured.

The degree to which an input signal is amplified (or attenuated) to allow greater accuracy and

resolution; can be expressed as ×n or ±dB.

The arrangement or operation of a circuit so that signals from another circuit or device do not

affect the isolated circuit.

In reference to Daq devices, isolation usually refers to a separation of the direct link between the

signal source and the analog-to-digital converter (ADC). Isolation is necessary when measuring
high common-mode voltage.

Some transducers produce a voltage in linear proportion to the condition measured.  Other

transducers (e.g., thermocouples) have a nonlinear response.  To convert nonlinear signals into
accurate readings requires software to calibrate several points in the range used and then
interpolate values between these points.

 A device that collects signals from several inputs and outputs them on a single channel.

The value of a signal on a channel at an instant in time.  When triggered, the ADC reads the

channel and converts the sampled value into a 12- or 16-bit value.

The channels that are selected for sampling.

A programmable device that manages channels and channel-specific settings.

An operation that gathers samples from multiple channels at the same instant and holds these

values until all are sequentially converted to digital values.

The single-ended mode measures a voltage between a signal line and a common reference that

may be shared with other channels.  (Also see differential mode).