If you can’t think outside of the box — get rid of the box

Like many electronic devices, PLC (programmable logic controller) production is being held up by a global shortage of semiconductors, which has no signs of abating. In fact, many estimates predict the crisis to continue until 2024. So, what can manufacturers do to find a quicker solution to lengthy lead times?

PLC alternatives

A hard or traditional PLC is a specific piece of hardware, with control capabilities as its only function. Within the PLC device is its central processing unit (CPU). On the other hand, a soft PLC is a piece of software capable of carrying out all the functions of a hard PLC’s CPU. However, a soft PLC can exist on hardware alongside other pieces of software.

Soft PLCs have existed since the 90s – used in PC-based control systems as a result of the rise of the Windows operating system. While early adopters reaped the immediate benefits of combining PLC control and the human machine interface (HMI) of a PC, the technology was less reliable than hard PLCs, and it was difficult to efficiently run multiple workloads on a single device. Plus, there’s the benefit of employee familiarity to consider – staff have experience with traditional PLCs so the set-up process is much easier, with minimal training required.

In the decades since then, soft PLC solutions have dramatically improved in terms of reliability and performance, thanks to advanced virtualisation technologies, real-time Linux operating systems and more powerful edge computing hardware. In fact, you could even say that most hard PLCs today are actually soft PLCs which run on dedicated hardware — software, wrapped in a box.

Plus, there’s the benefit of employee familiarity to consider. Staff have experience with traditional PLCs so the set-up process is much easier, with minimal training required. But, this is set to change.

To quote Chris Hoemke, Industry 4.0 manager at 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.”

Best of both

As demand has grown for soft PLCs, vendors have started to produce open PLCs, dedicated PLC hardware on which any software can be run. What this means is that companies, like COPA-DATA, can develop hardware independent soft PLCs that can be run on a wide range of controllers. Open PLCs combine the advantages of hard PLCs, like reliability and ruggedness, with the benefits of a soft PLC, including versatility, lower costs and standardisation.

In cases where there is a long wait on PLC hardware, why delay the entire project when you can run PLC code on a PC or another controller? By choosing an open PLC, it’s possible to get the automation project up and running as soon as possible using the software element, and then to easily transfer all processing to the dedicated PLC hardware once it arrives.

Choosing a soft PLC

If hard PLC production delays are causing manufacturers to turn to soft PLCs as an immediate solution, where do they start?

COPA-DATA’s zenon software offers a built-in PLC environment that engineers can access through a shared database. This simplifies the control process, meaning engineers only need to create objects once and can repeatedly access them within the system.

The zenon software platform offers all the functionality of a PLC, as well as a comprehensive suite of additional features designed to improve process visualisation and control, plus data acquisition, management, and analysis.

zenon is designed to provide an out-of-the-box, all-in-one platform to the challenges associated with digital transformation. So, manufacturers can rest assured that not only have they resolved their controller issues, they’ve also taken the first step towards a more efficient plant and data-driven decision making process.

As manufacturers face lengthy waits for PLC hardware, they should turn to disruptive technology for a solution.

Today’s soft PLCs promise all the functionalities of a hard PLC, without the wait. COPA-DATA’s zenon software offers flexibility and versatility that’s able to be used with hardware options from a range of different brands.