Chapter 6, Problem 7P

Program Plan Intro

Programmable Logic Controller (PLC):

• PLC is a specialized computer used in industrial segments to control machines and process.
• PLC is program that consists of a set of instructions which resembles the controlling functions needed to perform specific tasks.
• The function of PLC is similar to that of a relay and hence, in an industrial segment a relay is greatly replaced by a suitable PLC.
• When compared to general Personal Computer (PC), a PLC is available in small and tiny sizes.
• The basic architecture of a PLC consists of an input-output interface module and a small Central Processing Unit (CPU) that runs by controlling programming language.

Given:

The following motor control specifications must be satisfied by the ladder logic program.

• Three start/stop pushbutton stations are used to start and stop the motor.
• One Normally Open (NO) start pushbutton and one Normally Closed (NC) stop pushbutton will be contained by each start/stop station.
• Motor OL contacts are hardwired.