Mitsubishi Electronics FX1S manual What is a Programmable Controller?

Models: FX1S

1 120
Download 120 pages 31.35 Kb
Page 20
Image 20

Introduction 1

1.2What is a Programmable Controller?

FX1S

FX1N

FX2N

FX2NC

A Programmable Logic Controller (PLC or programmable controller) is a device that a user can program to perform a series or sequence of events. These events are triggered by stimuli (usually called inputs) received at the PLC or through delayed actions such as time delays or counted occur-rences. Once an event triggers, it actuates in the outside world by switching ON or OFF electronic control gear or the physical actuation of devices. A programmable controller will continually ‘loop’ through its internal ‘user defined’ program waiting for inputs and giving outputs at the programmed specific times.

Note on terminology:

The term programmable controller is a generic word used to bring all the elements making the control system under one descriptive name. Sometimes engineers use the term ‘Programmable Logic Controller’, ‘PLC’ or ‘programmable controller’ to describe the same control system.

The construction of a programmable controller can be broken down into component parts. The element where the program is loaded, stored and processed is often known as the Main Processing Unit or MPU. Other terms commonly heard to describe this device are ‘base unit’, ‘controller’ and ‘CPU’. The term CPU is a little misleading as todays more advanced products may contain local CPU devices. A Main CPU (or more correctly a Main Processing Unit) controls these local CPUs through a communication network or bus.

1.3What do You Need to Program a PLC?

FX1S

FX1N

FX2N

FX2NC

A variety of tools are available to program the Mitsubishi FX family of PLCs. Each of these tools can use and access the instructions and devices listed in this manual for the identified PLC.

HPP

FX-10P-E FX-20P-E

FX1S

FX1N

FX2N

FX2NC

Opto-isolated

RS232/

RS422 interface

Personal computer

Melsec MEDOC

Melsec Medoc Plus

SW1PC-FXGPEE

FX-PCS-WIN-E

1-2

Page 20
Image 20
Mitsubishi Electronics FX1S manual What is a Programmable Controller?, What do You Need to Program a PLC?