Relay logic is a hard wired control system using instrumentation, switches, timers, relays, contactors, motors and actuators. Traditional machine and process automation was accomplished using relay logic. Automating a machine using relay logic requires a mass of wiring and magnitude of devices to perform even the simplest of tasks. Some of the other problems with…

In the very early days of PLC programming ladder diagrams were configured and loaded into a PLC using dedicated hand held programmers. These hand held programmers were extremely slow and tedious to use. Programming was made a lot easier with the introduction of PC’s and interface software using text based operating systems such as the…

A ladder logic simulator is a software application that lets you simulate the operation of a PLC ladder diagram with a personal computer, mobile phone or tablet. It allows you to test your PLC ladder diagram without the need to purchase any PLC hardware. A ladder logic simulator also has the ability to control the…

PLC toggle logic emulates the function of flip flop circuits that are commonly used in electronics and computer systems. What is a Flip Flop in a PLC? You may have heard of a flip flop in electronics and computer systems, but what is a flip flop in a PLC? A flip flop in PLC programming…

PLC sequencer logic is an essential component to have in your quiver of ladder logic sample code.It forms the backbone to the majority of processes for industrial automation. Applications that require sequencer logic include conveyor systems, palletizing machines, batching plants, packaging machines, storage and retrieval systems and the list goes on and on. A sequence…

A PLC (Programmable Logic Controller) has some similarity to a personal computer (PC). It has a microprocessor, memory, input and output interfaces. However, unlike a PC, it does not have a keyboard, mouse, monitor or hard disk. And before for you ask, no – it can’t surf the net, check your social media status or…

Today competition in the industrial automation industry is fierce with companies being driven to become PLC manufactures and develop their own PLC brands in order to keep up and stay in front of the technology curve. All the big industrial automation brands are now manufacturing their own PLCs. Some of the major PLC manufacturers have…

In this article we’ll look at basic PLC architecture, the different types of PLCs used in industrial automation, advantages and disadvantages of PLC types and compare them in a handy reference table. What Is PLC Architecture? The term PLC architecture refers to the design specification of the various PLC hardware and software components and the…

A PLC (Programmable Logic Controller) is made up of both hardware and software components. The PLC hardware refers to the physical components that make up a PLC system. Whereas the PLC software refers to the PLC’s operating system and application program that are stored in the PLC’s memory. PLC hardware is a term that describes…

Ladder logic is a programming language that is used to program a PLC (Programmable Logic Controller). It is a graphical PLC programming language which expresses logic operations with symbolic notation using ladder diagrams, much like the rails and rungs of a traditional relay logic circuit. Ladder logic is a fast and simple way of creating…

The ladder logic symbols that are used in PLC programming have been derived from traditional relay logic control circuits. If you have a basic knowledge of electric circuits then getting started in ladder logic programming should be a breeze. If not, don’t worry, ladder logic is a graphical programming language and getting to know the…

Experience tells us that once a piece of ladder logic is created that accomplished a specific task it can be re-used in other areas of the program and in other applications as well. So by creating ladder logic programming examples we can speed up or overall programming time. Constructing a program is then a simple…

The PLC timer simulates the function of traditional timer relays. Initially, timer relays were utilized in relay logic circuits and were mechanical in nature. Over time, the mechanical timer relays were replaced by electronic timer relays and now, in modern times, they reside in the PLC as software timers. A PLC timer is an instruction…

PLC timers are frequently used in ladder logic programming. There are many different types of PLC timers, each with their own unique operation and application. Here we will explore some real world PLC timer examples, draw out the ladder diagrams and explain their operation. A common real world example of using an ON delay timer…