Definitions Of Programmable Logic Controller (PLC)

Programmable Logic Controllers (PLC) is a computer that is easy to use electronic or user-friendly control functions that have for various types and levels of difficulty diverse. Definition Programmable Logic Controller is electronic systems that operate digital and designed for use in the environmental industry, which uses a memory system that can be programmed for storage in the internal instructions that implement specific functions such as logic, sequence, time, counter and operating aritmatik to control the engine or through the process modules I / O digital and analog.

Based on the concept of PLC name is as follows:

Programmable
Show ability in terms of memory to store programs that have been made that easily changed the function or usefulness.

Logic
Shows the ability to process the input in the aritmatik and Logic (ALU), which is conducting operations compare, enumerate, multiply, divide, reduce, inverter, AND, OR, and others.

Controllers
Shows the ability to control and manage processes that produce the desired output

PLC is designed to replace a series of relay sequensial in a control system. In addition can be programmed, the tool can also be managed and operated by people who do not have the knowledge in the field of operation of the computer specifically. PLC has a programming language that is easily understood and can be operated when the program was created by using the software in accordance with the type of PLC used is entered.

This instrument works based on inputs that are depending on the circumstances and at a certain time then that will or ON-OFF-I output-output. '1' shows that the situation is expected to be met while the '0' situation is not expected to be met. PLC can also be applied to the control system that has a lot of output.

PLC Functions

A. In general
PLC function and usefulness in practice PLC can be divided in general and specifically. PLC functions are as follows:

Control sequence
PLC to process the input signal into a binary output that is used for the purpose of processing techniques sequentially, in order to maintain the PLC step in the right sequence of the process.

Monitoring Plant
PLC continually monitors the status of a system (such as temperature, pressure, high altitude) and take the necessary action in connection with a controlled process (for example, the value has exceeded the limit) or display a message on the service.

B. Special functions
PLC to provide input to the CNC (Computerized Numerical Control). Some PLC can provide input to the CNC to the interests of further processing. CNC when compared with the PLC has a higher accuracy and more expensive. CNC is usually used for the finishing process, establish working object, technology molding and so forth.

The working principles of a PLC is to receive input signals a process manageable, then do a series of instructions to the logic input signals in accordance with a program stored in memory and generate output signals to control the Actuator or other equipment.