Friday, 16 September 2011

What is Programmable Logic Controller ?

A Programmable Logic Controller (PLC) is nothing but a digital computer. It is also called as a programmable controller. The PLC is used for the automation of electromechanical processes. The control of machinery on factory assembly lines is done by the PLC.

There are six input and four output devices in the PLC. There are input units for Push Button Start, Sensor 1 Reverse and Sensor 1 Forward, Sensor 2 Reverse and Sensor 2 Forward and Emergency Stop. The output units are there for Cylinder 1 Forward and Cylinder 1 Reverse and Cylinder 2 Forward and Cylinder 2 Reverse. These devices are connected to the sensors and actuators. They may be built into a simple Programmable Logic Controller.

The PLCs can be described as an elementary component of the state of the art automation solutions. The guarantee of success of these controllers can be had from its features like easy handling, robustness, etc. Infact, the robustness is a key factor for the success of any PLC.

Most of the latest and sophisticated PLCs are easy to use and require no fan.
Unlike normal computers, these machines are protected from the effects of moisture, heat, dust, etc.

The basic programming languages like LAD, FBD, STL are used for programming and configuring.

So many topics are covered in the training program of PLC. Some of them are:

(1).History of Automation

(2).Basic &Architectural Evolution of PLC

(3). Role of PLC in automation

(4).Various ranges available in PLCs

(5). Types of Inputs & outputs

(6). Source Sink Concept in PLC

(7). AI, AO, DI, DO Parameterization and configuration

(8). Truth table implementation

(9). Ladder builder Keyence PLC and Omron PLC Simulator

(10). Timer Blocks programming & Counter Block programming

(11). Concept of flags, Scan cycle

(12). Live Interface Allen Bradley, Siemens S7-300 & GE-Fanuc, Mitsubishi, ABB, Delta PLCs

(13). Upload, download, Monitoring of programs

(14). Load / Read / Write /Move /Leading edge / Trailing edge instructions

(15). Compare / Add / Sub /Master control /set /reset function

(16). Troubleshooting and fault in PLC