An age-old debate in PLC programming: investigating the uses and caveats of latching software commands versus seal-in ladder logic for industrial control applications. One of the most popular programming languages used with industrial automation controllers today is called ladder logic, following in the footsteps of the previous method of control which used interlocking electrical relays. … Read more
This article discusses PLC Sequencer Logic and the steps needed to accomplish PLC sequencing. PLCs have a set of inputs from sensors on which logical, and mathematical operations can be done. The output of the PLC is used to control the operating characteristics of the machine or process to which it is connected. Industrial PLC … Read more
Learn how to connect analog inputs, either voltage or current, to the Phoenix Contact’s IIoT PLC platform and design simple data processing programs with the PLCnext Engineer IDE. Before you get started, be sure to check out our recent introduction to discrete I/O with the PLCnext platform. Analog signals from sensors allow engineers to monitor … Read more
For most systems, there are various languages meant for specific purposes, including Function Block, Sequential Charts, and Structured Text. By far, the most common programming language for PLCs consists of rungs of if-then logic, similar to an electrical line diagram, going by the name of ‘Ladder Logic.’ Many programmers have quite likely been exposed only … Read more
Many PLC commands are well-known to programmers, including contacts, coils, timers, and counters. But a less-common instruction is the one-shot, capable of harnessing the incredible processing speeds in a CPU. One-Shot Functions In a previous article, I wrote about how to use timers in ladder logic. A typical next step is to discuss counters, being … Read more
In this first of an upcoming series, we investigate Siemens as a major PLC manufacturer, learning about the hardware, software, and key applications of each product lineup. Siemens AG is the largest energy and industrial manufacturing company in Europe, and with more than 170 years of history, it is also an innovator in many fields. … Read more
Learn how to get started with Phoenix Contact’s PLCnext and Engineer software, a platform that ultimately provides a PLC environment for plant control as well as an OS for more advanced IIoT projects. As we examine the scope of modern control systems around the world, there are three distinct categories of controllers. At the most … Read more
There are a lot of companies considering in-house automation or consulting with integrators for automated systems. But where do you start, and how do you even pick a project for automation? One of the most impressive things in the manufacturing world is when products are being made with little or no intervention, giving operators more … Read more
Sensor networks with built-in logic functions can save cost and program execution speed, but what are those various logic functions, and when might they be preferred over normal PLC ladder logic? The logic functions that exist within some sensors are fundamental operations that process input signals to determine an output. These functions help the sensor … Read more
Learn how to write a ladder logic program to assign a string value to a data register and share that register with any HMI compatible with Mitsubishi’s MELSEC PLC series. Human-machine interface (HMI) panels are often designed for the control and display of essential data from the control system to the users. From interaction with … Read more