Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual - Manual (Page 69)

1 Publication 1746-UM026A-EN-P - September 2003
Glossary
You should understand the following terms and abbreviations before
using this guide. For the definitions of terms not listed here, refer to
Allen-Bradley Industrial Automation Glossary, publication AG-7.1
Channel Refers to one of the sets of signal interfaces
available on a module’s terminal block.
Channel update
time For analog outputs, the time required for the
channel to convert the data received from the
processor to analog output signals at the
terminals.
Chassis A hardware assembly that houses devices such
as I/O modules, adapter modules, processor
modules, and power supplies.
Configuration
word Contains the channel configuration
information needed by the module to
configure and operate each channel.
Information is written to the configuration
word through the logic supplied in your
ladder program.
D/A Refers to digital-to-analog conversion. The
conversion produces an analog output signal
whose magnitude is proportional to the digital
value.
Data scaling The data format that you select to define the
logical increments of the channel data word.
Data word A 16-bit integer that represents the value of
the analog output channel. The channel data
word is valid only when the channel is
enabled and there are no channel errors.
LSB (least signifi-
cant bit) The bit that represents the smallest value
within a string of bits. The weight of this value
is defined as the full scale range divided by
the resolution.
Module ID code A unique number associated with each 1746
I/O module. The code defines for the
processor the type of I/O or specialty module
residing in a specific slot in the 1746 chassis.
Module update
time See channel update time.
Overall accuracy The worst-case deviation of the signal over the
full range, expressed in percent of full scale.
Rack A hardware assembly that houses devices such
as I/O modules, adapter modules, processor
modules, and power supplies.