Motor ON/OFF application using retentive timer and retentive timer instruction of the PLC.

Motor ON/OFF application using retentive timer and retentive timer instruction of the PLC.

Problem Description

Motor ON/OFF application using retentive timer and retentive timer instruction of the PLC.

Problem Diagram

The retentive timer is used to store the time in the application.This timer will be ON when input status changes from 0 to 1.

Here we used retentive timer for the application because we want to store the time or hold the timer.

Even if input signal state changes from 1 to 0 , time will not become zero but timer will accumulate the time.

And when delay is completed , motor will be ON.

In case of PLC take NO contact of the switch and provide retentive timer before output coil (here motor).

When we start switch retentive timer will be start and switch is OFF, it will accumulate the time.

And after delay motor will be ON.

What is PLC?.

What is PLC?.

A  PLC (PROGRAMMABLE LOGIC CONTROLLER) may be a solid state system that unceasingly monitors the standing of devices connected as inputs.

Based on a user program, hold on in memory, it controls the standing of devices connected as outputs.

A digital device that uses a programmable memory to store directions and to implement specific functions such as logic, sequence, timing, count and arithmetic to manage machines and method.

It uses a programmable memory to store the directions and specific functions that embody On/Off management, temporal order count, sequencing, arithmetic and knowledge handling.

A PLC may be a pc designed to figure in Associate in nursing industrial atmosphere.

What is CPU?

What is CPU?

CPU is the brain of the PLC

It is controlled by the program called the operating system or OS.

And the execution is the collection of the program which is stored in the memory.

Duties of the CPU?

Duties of the CPU?

The CPU reads the inputs and processes the control program and controls the outputs as per program.

CPU provides internal memory, timers and counters and other instruction set.

Commands connected outputs can be controlled based on program. For examples light, fan etc.

Inputs examples for the PLC

Inputs examples for the PLC

Switches and Pushbuttons

Sensing Devices

Limit Switches

Photoelectric Sensors

Proximity Sensors

Condition Sensors

Pressure Switches

Level Switches

Temperature Switches

Vacuum Switches

Float Switches

Encoders

Jog function in PLC using start/stop button

Jog function in PLC using start/stop button



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Logo PLC examples for learning purpose

Outputs examples for the PLC

Outputs examples for the PLC

Valves

Motor Starters

Solenoids

Actuators

Control Relays

Horns & Alarms

Stack Lights

Fans

Counter

Pumps

Printers

Power supply for the PLC

Power supply for the PLC

A power supply is needed to provide power to the PLC and any other

Modules in the panel.

Power supplies come in various forms:

Power supply

External power supply

Standalone power supply

List of items required when working with PLC.

List of items required when working with PLC.

Programming device (laptops or PC).

PLC software .PLC manufactures have their own software for programming.

Communication cable

Back up copy of the ladder program.

Documentation (ladder program, operation manuals etc. and drawing.