Rockwell Automation 1790D-NOV2/TNOV2 CompactBlock LDX Analog Modules - Manual (Page 95)

1 Publication 1790-UM001A-EN-P - March 2002
Glossary
The following terms and abbreviations are used throughout this
manual. For definitions of terms not listed here refer to Allen-Bradley’s
Industrial Automation Glossary, Publication AG-7.1.
A/D Converter– Refers to the analog to digital converter inherent to
the module. The converter produces a digital value whose magnitude
is proportional to the magnitude of an analog input signal.
analog input module – A module that contains circuits that convert
analog voltage or current input signals to digital values that can be
manipulated by the processor.
channel – Refers to analog input or output interfaces available on the
module’s terminal block. Each channel is configured for connection to
a variable voltage or current input or output device, and has its own
data and diagnostic status words.
channel update time – The time required for the module to sample
and convert the input signals of one enabled input channel and
update the channel data word.
configuration word – Contains the channel configuration
information needed by the module to configure and operate each
channel.
D/A Converter – Refers to the digital to analog converter inherent to
the output module. The converter produces an analog dc voltage or
current signal whose instantaneous magnitude is proportional to the
magnitude of a digital value.
data word – A 16-bit integer that represents the value of the analog
input or output channel. The channel data word is valid only when
the channel is enabled and there are no channel errors. When the
channel is disabled the channel data word is cleared (0).
full scale – The magnitude of voltage or current over which normal
operation is permitted.
full scale error – (gain error) The difference in slope between the
actual and ideal analog transfer functions.
full scale range – (FSR) The difference between the maximum and
minimum specified analog input values.