Rockwell Automation 1746-XXXX SLC 500 4-Channel Analog I/O Modules User Manual - Manual (Page 13)

1 Publication 1746-UM005B-EN-P - June 2004
Chapter
1
Overview
This chapter describes how analog is used and provides two
application examples of analog. The types of available analog
modules and their related specifications are also described.
How to Use Analog Analog refers to the representation of numerical quantities by the
measurement of continuous physical variables. Analog applications
are present in many forms. The following application shows a typical
use of analog.
In this application the processor controls the amount of fluid placed in
a holding tank by adjusting the percentage of the valve opening. The
valve is initially open 100%. As the fluid level in the tank approaches
the preset point, the processor modifies the output to degrade closing
the valve 90%, 80%, adjusting the valve to maintain a set point.
Types of Analog Modules The following sections provide an overview of the various analog
modules.
Level Sensor
CPU
Analog Input
Analog Output
Valve
Analog I/O
Module