Rockwell Automation 1769-IF4XOF2 Compact 8-Bit Low Resolution Analog I/O Combination Module - Manual (Page 11)

1 Publication 1769-UM008A-EN-P - November 2001
Chapter
1
Overview
This chapter explains how analog data is used and describes the
1769-IF4XOF2 combination analog I/O module. Included is
information about:
•
How to Use Analog I/O on page 1-1
•
General Description of the Module’s Hardware and Diagnostic
Features on page 1-2
•
Overview of the Analog System on page 1-4
How to Use Analog I/O 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 data.
In this application, the processor controls the amount of fluid in a
holding tank by adjusting 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 close the valve 90%, 80%, and so
on, continuously adjusting the valve to maintain the fluid level.
Controller
Analog I/O
Module
Valve
Level Sensor
Analog input wired
to tank
Analog output
wired to valve