Drives & Controls Magazine November/December 2022

32 n CONTROLLERS AND SOFTWARE November/December 2022 Solving the PLC shortage: think outside the box F or manufacturers looking to update their industrial automation systems, there may be a significant obstacle in their way — the availability of PLCs (programmable logic controllers). Like many electronic devices, production of PLCs is being disrupted by the global shortage of semiconductors, which shows little sign of abating. In fact, many estimates predict the crisis will continue until 2024. So, what can manufacturers facing lengthy lead times do? The traditional“hard”PLC is a piece of hardware with industrial control as its only function. At the heart of the controller is a CPU (central processing unit). A soft-PLC is a piece of software that can carry out all of the functions of a hard PLC’s CPU. A soft-PLC can run on hardware alongside other pieces of software. Soft-PLCs have existed since the 1990s. As use of theWindows operating system became widespread, PC-based control systems based on soft-PLCs emerged. While early adopters reaped the immediate benefits of combining PLC control with the HMI (human-machine interface) capabilities of a PC, the technology was less reliable than hard PLCs, and it was difficult to run multiple workloads efficiently on one device. In addition, users were familiar with traditional PLCs, so the set-up process was much easier, and needed minimal training. In the decades since then, however, soft-PLCs have improved dramatically in terms of their reliability and performance, thanks to advanced virtualisation technologies, real-time Linux operating systems and powerful edge computing hardware. In fact, you could say that most of today’s hard PLCs today are actually soft-PLCs that run on dedicated hardware— software wrapped in a box, if you will. Also the familiarity factor is set to change. To quote Chris Hoemke, Industry 4.0 manager at the market analyst, Infosys:“Changing workforce demographics are making it more difficult to find traditional (hard) PLC programmers and easier to find programmers familiar with object- oriented languages. The next generation workforce will be familiar with docker containers, virtual machines, Git repositories and object-oriented programming. This will shift the workforce‘familiarity’advantage that hard PLCs currently have, to soft-PLCs.” As demand for soft-PLCs has grown, vendors have started to produce “open” PLCs – dedicated PLC hardware on which any software can run. They are developing hardware-independent soft-PLCs that can run on a wide range of controllers. Open PLCs combine the advantages of hard PLCs, such as reliability and ruggedness, with the benefits of soft-PLCs such as versatility, lower costs and standardisation. If you are having to wait a long time for PLC hardware, why delay entire projects when you could be running PLC code on a PC or another controller? By choosing an open PLC, it’s possible to get an automation project up and running as soon as possible using the software element, and then transfer all processing easily to the dedicated PLC hardware when it arrives. Choosing a soft-PLC So, if hard PLC production delays are causing you to turn to soft PLCs, where do you start? Software such as Copa-Data’s zenon platform offers a PLC environment that engineers can access through a shared database. This simplifies the control process, meaning that engineers only need to create objects once and can then access them repeatedly within the system. Such platforms offer all the functions of a PLC, as well as additional functions designed to improve process visualisation and control, data acquisition, management and analysis They can provide an all-in-one, out-of-the-box answer to the challenges associated with digital transformation. They can resolve manufacturers’controller issues, and offer a first step towards more efficient plants and faster, data-driven decision-making. Manufacturers faced with lengthy waits for PLC hardware, can now turn to a disruptive technology. Today’s soft-PLCs promise all the functions of a hard PLC, without the delay. n The semiconductor shortage is causing disruption and delays to the production of PLCs. With significant lead times for some new PLCs, manufacturers have to consider alternatives. Stefan Reuther, chief sales officer at Copa-Data, advocates a software- based approach to eliminate the dependency on hardware. Some automation platforms offer a PLC environment that engineers can access through a shared database