Chapter 1
DAQ System Overview
©
National Instruments Corporation
1-5
To measure signals from these various transducers, you must convert them
into a form that a DAQ device can accept. For example, the output voltage
of most thermocouples is very small and susceptible to noise. Therefore,
you may need to amplify or filter the thermocouple output before digitizing
it. The manipulation of signals to prepare them for digitizing is called
signal conditioning.
For more information about sensors, refer to the following documents.
•
For general information about sensors, visit
ni.com/sensors
.
•
If you are using LabVIEW, refer to the
LabVIEW Help
by selecting
Help»Search the LabVIEW Help
in LabVIEW, and then navigate to
the
Taking Measurements
book on the
Contents
tab.
•
If you are using other application software, refer to
Common Sensors
in the
NI-DAQmx Help
, which you can access from
Start»All
Programs»National Instruments»NI-DAQ»NI-DAQmx Help
, or
the
LabVIEW 8.x Help
.
Signal Conditioning Options
SCXI
SCXI is a front-end signal conditioning and switching system for various
measurement devices, including E Series devices. An SCXI system
consists of a rugged chassis that houses shielded signal conditioning
modules that amplify, filter, isolate, and multiplex analog signals from
thermocouples or other transducers. SCXI is designed for large
measurement systems or systems requiring high-speed acquisition.
System features include:
•
Modular architecture
—Choose your measurement technology
•
Expandability
—Expand your system to 3,072 channels
•
Integration
—Combine analog input, analog output, digital I/O, and
switching into a single, unified platform
•
High bandwidth
—Acquire signals at an aggregate rate of up to
333 kHz
•
Connectivity
—Select from SCXI modules with thermocouple
connectors or terminal blocks