10 Latest PLC Technology Trends

A Programmable Logic Controller (PLC) is an automated system that collects data from different input devices such as sensors that monitor parameters like storage levels, pressure, temperature…etc. Then, using its programmed software logic, the PLC processes the collected data, makes appropriate logic-based decisions, and conveys the output instructions and commands to control processes and machines. PLCs have been around for nearly 50 years, and are still considered the best option for a wide range of industrial automation applications. Despite their age, PLC technology has continued to evolve and PLCs are expected to maintain their dominance in the industrial automation world for years to come. Here are some of the 10 latest technological developments through which PLC technology is advancing and adapting to the times.

1) Compact size, Faster Processing Time and Cost Optimization 

Technological improvements such as the shrinking size of processors, circuit boards, and other components; are greatly transforming the electronics industry. More so, these improvements are starting to impact PLCs, following the introduction of smaller PLCs in the micro and nano classes. Though smaller, these new PLCs are equipped with faster processors with improved cycle time, greater memory capacity, and new communication enhancements.

Previously, the aforementioned features were only a characteristic of higher-level and mid-range PLC systems, but in response to market demands, many of the higher-end features and functions are migrating to lower-end PLCs. This has led to a shift from larger PLCs to smaller ones, as even those in the micro and nano classers are capable of remote connectivity, Ethernet communication, onboard PID with auto-tune, motion control, and other control functions.

For example, PLC manufacturers are leveraging the drastic declines in size and costs of solid-state memory. This has allowed a huge increase in local data storage, enabling the use of PLCs in numerous applications which initially required expensive data acquisition systems. Also, reductions in memory size have created a pathway for many other features, like the on-board storage of information related to products, which expedites troubleshooting of PLC-controlled systems.

Furthermore, the current PLCs are greatly benefiting from USB technology, which has made it very easy to program and monitor your control system while online. And as the USB technology continues to evolve, with the availability of micro and smaller mini-USB connectors, it is expected that these communication options will be integrated into smaller PLCs.

In addition to the USB readers, PLCs are also being integrated with SD cards, micro-SD and mini-SD cards, and other minute connectivity devices. These portable devices provide up to 32 GB of additional non-volatile memory to a PLC, as needed by the system integrator, machine builder, or end-user. This is a feature of the fast-moving consumer electronics industry whose integration with PLCs is quickly revolutionizing industrial control systems.

2) Improved Communications Network 

In the last few decades, especially in the early 1990s, an excessive variety of communication protocols and networks have been developed for use in industrial communication. This trend continues to further focus on real-time communication technologies, raw and connectivity speed of Ethernet as well as other industrial control networks for a vast range of applications. In their present form, high-end PLCs include multiple ports to support several communication protocols. But looking into the future, this is likely to change as users continue to demand more standardized Ethernet and Wireless communication options. Even though it’s a wireless age, industrial processes would require more robust wireless technologies with enhanced data integrity and improved communication range, before we can witness a convergence of industrial and commercial wireless communication protocols.

Though there has been great progress in this field, from the latest ZigBee (802.15.4) and Wi-Fi (802.11n) protocols to the use of mesh and wireless ad hoc networks (WANET) as well as the rise of Near Field Communication (NFC) and Industrial Bluetooth; none of these wireless technologies has proven capabilities for mission-critical operations often encountered plant floors. Therefore, in the future, a great deal of less critical PLC controlled applications in which real-time control isn’t essential, are likely to widely adopt wireless communication networks particularly in RTUs (remote terminal units).

3) PACs (Programmable Automation Controllers) and PLCs Merge 

Generally, a Programmable Automation Controller (PAC) is a hardened modular industrial controller which uses a PC-based processor and it provides a variety of programming options beyond the IEC 61131-3 programming languages. It is also referred to as Industrial PC or just IPC. PACs are considered more advanced compared to PLCs. However, over the years, PLCs have continued to evolve while adapting improvements in hardware technology, software, and communications. With high-end features making their way into lower-end PLC processors.

For example, larger memory capacities and high-speed processors have created an opportunity for the integration of advanced features with PLCs, such as motion control, simultaneous support for multiple communication protocols, and high-resolution vision systems. On the other hand, even with advanced features, PAC systems still maintain the simplicity that makes PLCs attractive to many end-users. Additionally, the capabilities of PACs have allowed users to stretch the envelope of what is considered conventional industrial automation, encouraging product designers to develop customized controllers to meet their needs.

During this evolution, many industrial controller suppliers have continued to tout the differences between PACs and PLCs. But in this same period of PLC versus PAC, the definition and features of each have changed and we have noted much faster advancements in both classes. Therefore, as each controller evolves, the more the functionality of the two will continue to merge. In fact, in the future, automation engineers are likely to not care about the nomenclature, instead, they will focus on the available features and performance as they specify their control systems.

4) The Open-Source PLC

Whenever we come across the term “open-source”, we think of a hardware design that is open source or a standardized non-proprietary PLC scripting language that should be implemented under a public license. However, the way the open-source era is influencing the PLC industry is quite comprehensive.

It is simply eliminating the idea of a PLC altogether, by suggesting that the PLC technology should be based on a computer system like Raspberry Pi. An increasing number of companies have taken up the Raspberry Pi and built it into a system that is rugged and can withstand extreme environments for industrial applications. In this case, a Raspberry Pi is typically paired with one or more circuit boards that provide the digital/analog and I/O features which make up a conventional PLC. With Raspberry Pi, the additional circuit boards are designed with the capability to withstand high currents and voltages and to provide the isolation required in an industrial environment. Therefore, in terms of hardware, the Raspberry Pi can at least be integrated into industrial automation through such extensions.

In terms of software, single-board computers such as Raspberry Pi are not designed to be programmed with IEC 61131-3 standard languages like Function Block Diagram or Ladder Logic used to program PLCs. Instead, Raspberry Pi runs on an operating system like Linux or a derivative of Linux, and such an O/S is best accessed by high-level programming languages including Java, C and C++, and other higher levels of abstraction which purely use mathematical expressions. This is quite different from the bit-bashing environment of Microcontrollers Units (MCUs), that support Ladder Diagram and other IEC languages.

However, some companies like Phoenix Contact are taking advantage of the open-source disruptions in the PLC market, to create open programming platforms like “PLCnext”. The “PLCnext” is an open-programming environment that is based on Linux O/S but it targets PLC applications. It achieves this by providing system designers with options for configuring their control systems, using either higher-level IT technologies such as HTML or based on IEC 61131-3 programming languages.

5) PLCs Designed for Industry 4.0 

Many technological innovations like artificial intelligence, clouding computing, sophisticated sensors as well as big data analytics, have and continue to significantly impact the landscape of manufacturing industries. These industrial technological advancements are commonly referred to as Industry 4.0. In this new industrial reality, PLCs have continued to play a key role as the main control, input hub, and interface for human operators.

To remain as the central processor for real-time manufacturing operations, PLC technology is being developed further to allow better communication with multiple input sensors over the Industrial Internet of Things (IIoT). This has enabled PLCs to accurately collect huge amounts of data and to deliver it to machine learning programs much more easily. For example, data from input sensors and other devices in conjunction with PLC data can be integrated to illustrate the “big picture” which results from the collection of the “big data”.

Plant managers and data analysts can then use Analysis tools to better track the big data, leverage resources, carry out logistics, schedule jobs and plan tasks like supplier timing in an effort to create highly efficient manufacturing processes. In addition, the “big data” can also be tracked and analyzed for optimal performance and preventative maintenance of machines and equipment within the scope of the manufacturing systems.

6) Unified Programming Environment 

There has been a trend of combining Human Machine Interfaces (HMI), motion control and PLC into a unified programming environment. In the next several years, this trend is likely to continue. Following suit will be the integration of a PLC with an HMI processor on the same rack, and the inclusion of the monitor as an external option or as part of the package. This technology allows the configuration of either an HMI module or HMI processor with a PLC I/O rack.

A unified programming environment is ideal for most system designers and control engineers if it is not too overwhelming. Some of the key benefits of combining these modules include an overall reduction in program development time and a reduced learning curve. But to get the most from such a tool, it must be properly thought out so that it is easy to navigate.

7) More Power, Wider Data Sharing 

PLCs are becoming more powerful, allowing them to be equipped with capabilities that earlier were only exclusive to the workstation and Personal Computer (PC) domain. This has translated to quicker and cheaper sharing of data from the PLCs situated on the factory floor, to the human operators at the Control Level. Some of the features that enable current PLCs to widely share data include Internal Relational Databases, FTP Servers, Web Servers, and sending E-mail.

The Web Servers, for instance, allow PLCs to host a website on the internet or the company’s intranet. The web server in turn allows you to access Real-time data logging and acts as a backup HMI for a work cell or machine(s). Also, the webserver feature in some PLCs can store documentation that enables you to view machine schematics and drawings, as well as operator and maintenance manuals with short video clips. Hence, the capabilities of PLC web serves to vary depending on the model and manufacturer design specifications, from a single “canned” web page to full-blown sites using JAVA and XML-based technology. Web servers in PLCs are probably the most widely used of the new data-sharing technologies in PLCs.

Second to the PLC web server, is the Send-Email function which simplifies and automates the exportation of critical and production data from a PLC to a human operator. It enables a PLC control program to issue production data, status change, material usage reports, alarms, and PLC internal data. Interestingly, you can send alarm messages using the PLC Send E-mail feature to the Maintenance personnel via cell phones or alphanumeric pagers within a short period of time.

8) Advancements in Ladder Logic

Fifty years ago, the Ladder Diagram (LD) replaced the hardwired relay logic as a PLC programming language. The LD language kept things simple for system engineers and designers who were used to relay logic, but at the time it had some limitations, particularly in terms of data handling and process control.  

To address the challenges of ladder diagram, the IEC 61131-3 introduced other PLC programming languages such as Function Block Diagram (FBD), Structured Text (STX), Sequential Function Chart (SFC) and Instruction List (IL). However, developers of Ladder Diagram responded with its advancements which have surprisingly stayed relevant and powerful in programming industrial controllers. We could say all IEC languages have their strong points, like STX is well-suited for data manipulation. But Ladder Logic still forges on, and has remained a leader in terms of PLC programming languages by a wider margin. 

For instance, control system suppliers and end-users support installation of a large base of equipment, machines and processes controlled by PLCs that are programmed in Ladder Diagram. Also, there’s a large group of maintenance personnel, electricians, technicians and engineers who prefer the simplicity of ladder logic programming technology. Moreover, regardless of the hardware used, the LD language has gone a long way in creating the industry standard for programming PLCs and this trend is likely to continue in the coming years. 

9) PLC Designs that Withstand Harsh Conditions 

PLCs that are currently available in the market are rugged and designed to withstand extreme climatic events like cold snaps, floods, or heat waves; conditions that could potentially damage electronic devices including PLCs. These robust and sturdy PLCs designs are being made with more durable materials like fiber signals instead of electronic signals, making them well-suited for some electronically hostile plant floors. In addition, due to the advancements in IIoT technology (previously discussed), PLCs can now be housed in isolation of harsh environmental conditions and operated remotely from regions with less or zero electrical noise disruptions. This has proven to be of great benefit whenever there are sensitive processes and sensors which require precise actions and monitoring.

10) Higher Security

Cybersecurity is becoming increasingly essential with the rise of interconnected devices in this era of the Internet of Things. For instance, interfering with the visibility of sensor systems or shutting down sensors, could cause work sites and plants to shut down; resulting in enormous losses. To curb or prevent such occurrences, industrial controller suppliers are responding by delivering PLCs with built-in state-of-the-art security enhancements. For example, in 2016 Honeywell Process Solutions (HPS) launched ControlEdge™ Programmable Logic Controller. This PLC is designed with built-in cyber security features to deter cyber-attacks. Moreover, it is a next-generation controller by Honeywell which leverages the power of the Industrial Internet of Things (IIoT).

What’s the Future of PLCs?

Since 1947, PLCs have been able to adapt to changing technological times and maintain their popularity in the industrial automation world. Looking into the future, the potential of PLCs is closely linked to the rapid development of Internet technologies, as the newer generation of industries will be more concerned with the reliability, flexibility, and safety of their control systems.

Industry 4.0 has already set the trend of industrial automation, with the introduction of “smart factory” models that combine elements of communication, electronics, and power supply to provide a multi-pronged solution to any given industrial control problem. This proves that PLCs will continue to be a core function in automated factory settings, as they become smaller, cheaper, faster, and more powerful. For more information or to discuss which equipment might be best for your application, please visit our website here, or contact us at [email protected] or 1-919-535-3180. 

This entry was posted on September 27th, 2021 and is filed under Uncategorized. Both comments and pings are currently closed.