Bench Talk

(Source: Buffaloboy – adobestock)

Rapid developments in industrial automation have made PLC or Programmable Logic Controllers (PLCs) an essential part of any manufacturing environment. PLC are digital computers used for industrial and commercial purposes. These computers are often connected to several input devices and perform based on pre-defined programs. PLCs are considered to be the advanced and most reliable form of conventional hard-wired relay logic, as they can be programmed or reprogrammed according to the application’s requirements and adapt to changes in the factory conditions without the need for changing wires. In this blog, we will discuss the role PLCs play in the further development of Industry 4.0, as well as interconnecting solutions that can assist manufacturers in better connecting their PLCs in their factories.

While PCs and smartphones can process multiple programs, PLC is designed to perform a single set or pre-defined task. Like normal computers, PLCs, also have a processor, buses, I/O modules, a programming unit, and a memory. The processor is the center of the device that regulates the programs after processing the inputs and then sends commands to the output device. They perform functions including logic operations, arithmetic operations, computer interface, and many more. Buses are communication paths to the PLC. The buses transmit data in binary form to the controller, as mentioned the PLCs work upon a logic, which is already programmed. This along with the data is stored in the memory. The I/O modules include all interfaces that connect the PLC to the other applications. It includes input units like sensors to output units like solenoids and motors.

From modular to integrated, there are several types of PLCs available today. Generally, these are designed to perform in extreme conditions. They are capable of withstanding high temperature, vibration, humidity, etc. These easily programmable devices have input and output interfaces within the controller. PLCs offer a cost-effective solution to control a complex system. In addition, PLCs offer a great deal of flexibility and the capability to be reused in order to support several applications with changing the programs.

PLCs are designed to control machinery such as robots or servo motors inside a factory. They are programmable computers packed inside rectangular cabinet boxes that can withstand extreme temperatures and moisture. Being modular, multiple units of these devices can be stacked to carry out additional controlling if desired. They can easily run codes that accept inputs from a sensor device and output the decision to an alarm, display, or printer. The codes are looped and triggered either by inputs or by a clock.

Before Industry 4.0, one PLC was used to handle a group of machines., With the introduction of Industry 4.0, multiple PLCs can be interspersed among the factory fabric with every robot or servo motor having their own controllers. The controllers must now talk with each other and to the cloud, do authentication over the factory Wi-Fi to remain secure, and respond to customer orders. Flexibility, speed, reliability, and compactness are not options here anymore.

So how can a Connected Controller be flexible, fast, reliable, and compact? They can have MPUs (processors) with multiple cores that can execute the same program to compare and catch any errors that compromise safety. It is also worth noting that MPUs with signal processing technology can offload mathematically intensive tasks leaving only the generic program execution to the main registers.

PLCs play a vital role in Industrial 4.0, which is why many factory designers are being tasked with deploying them. However, how do you integrate PLCs into a factory automation system? Amphenol offers many integration options.

Let's first examine the elements of a PLC. PLCs typically consist of a CPU module, interface module, communication module, power-supply module, and rack.

CPU Modules

CPU modules are considered the brains of the PLC. They run ladder-logic programs that automate factory processes. CPU modules have both internal and external connectors. Millipacs^® Vertical and R/A Receptacles from Amphenol are backplane connectors that help connect the CPU module to the PLC rack as well as the input module next to it. In addition, Minitek^® Board-to-Board 2.00mm Connectors are contained inside the CPU module. Additionally, the CPU module's input/output connectors include D-Sub and RJ45 connectors.

Interface and Communication Modules

The interface and communication modules also have D-Sub connectors that connect to D-Sub standard board mount connectors. This facilitates the communication between the modules and other components in the control cabinet, like the servo drive controllers and relays. Amphenol’s connectors such SAS PCIe and DDR4 support the data transferring units and communication with other systems in the network, mezzanine connectors like the BergStak^® 0.80mm/0.50mm interface the motherboard inside the PLC through add-in-cards.

PLC Racks

The PLC rack contains a series of Millipacs^® vertical headers that allow each module, such as a CPU, communication, and power supply, to be connected to the rack. The PLC rack serves as the communication and synchronization center of the PLC. In addition, Minitek^® MicroSpeed, Minitek^® Pwr, and Minitek^® 1.25mm, USB Connectors and Modular Jacks (RJ45) are also found in a PLC rack.

The need to keep up with the rapid developments in industrial automation has made PLCs an essential part of any manufacturing environment. PLCs are powerful, robust programmable and reprogrammable modules that are used in harsh industrial and commercial applications to replace hard-wired relay logic. Like computers, PLCs are made up of many components that need to be connected to each other within their rack housings. Amphenol Communications Solutions offers a variety of interconnect solutions to help designers integrate more cost-effective PLCs solutions into their factories as PLCs continue to evolve with Industry 4.0.