PLC dealers and distributors in India
Automation Direct is a leading Supplier, Reseller, Dealer and distributor of PLC from various international brands in India supporting critical applications.
PLC stands for Programmable Logic Controller. They are industrial computers used to control different electro-mechanical processes for use in manufacturing, plants, or other automation environments.
PLCs vary in size and form factors. Some are small enough to fit in your pocket while others are large enough to require their own heavy-duty racks to mount. Some PLC’s can be customized with back planes and functional modules to fit different types of industrial applications.
PLCs are widely used in a variety of industries because they’re fast, easy to operate and are considered easy to program. PLCs can be programmed in several ways, from ladder logic, which is based on electromechanical relays, to specially adapted programming languages of BASIC and C, to name a few.
SCADA and HMI systems enable users to view data from the manufacturing floor and provide an interface for users to provide control input — and PLCs are an essential hardware component element in these systems.
PLC’s act as the physical interfaces between devices on the plant or manufacturing floor and a SCADA or HMI system. PLCs communicate, monitor and control automated processes like assembly lines, machine functions, or robotic devices.
A PLC’s functions are divided into three main categories:
- Input
- Output
- CPU
Most PLCs today use one of the following 5 programming languages:
- Sequential Function Charts.
- Instruction List
- Function Block Diagram
- Structured Text
- Ladder Diagram

There are two main types of inputs:
Data inputs from devices and machines, and data inputs that are human-facilitated. The input data from sensors and machines are sent to the PLC. Inputs can include on/off states for things like mechanical switches, buttons, and encoders. High/low states for things like temperatures, pressure sensors, and liquid-level detectors, or opened/closed states for things like pumps and values.