© National Instruments Corporation xi SCXI-1121 User Manual
About This Manual
This manual describes the electrical and mechanical aspects of the
SCXI-1121 and contains information concerning its operation and
programming. The SCXI-1121 is a member of the National Instruments
Signal Conditioning eXtensions for Instrumentation (SCXI) Series for the
National Instruments data acquisition plug-in boards. This board is
designed for signal conditioning of strain gauges, RTDs, thermistors,
thermocouples, volt and millivolt sources, and 4 to 20 mA sources or 0 to
20 mA process-current sources where high common-mode voltages exist.
The SCXI-1121 operates as four isolated input channels and four isolated
excitation channels. Each channel is isolated and independently
configurable via jumpers.
This manual describes the installation, basic programming considerations,
and theory of operation for the SCXI-1121.

Conventions

The following conventions appear in this manual:
<> Angle brackets that contain numbers separated by an ellipsis represent a
range of values associated with a bit or signal name—for example,
DBIO<3..0>.
This icon denotes a note, which alerts you to important information.
This icon denotes a caution, which advises you of precautions to take to
avoid injury, data loss, or a system crash.
This icon denotes a warning, which advises you of precautions to take to
avoid being electrically shocked.
bold Bold text denotes items that you must select or click on in the software,
such as menu items and dialog box options. Bold text also denotes
parameter names.
italic Italic text denotes variables, emphasis, a cross reference, or an introduction
to a key concept. This font also denotes text that is a placeholder for a word
or value that you must supply.