Why is soft PLC on the rise for industrial applications?
Hard PLCs are the go-to for industrial applications
Soft PLCs have been around since the 1990s, but they were pretty much side-lined until recently.
For many years, soft PLCs simply could not match the reliability of hard PLCs. Traditional PLCs (hard PLCs) use proprietary hardware and operating systems that are lightweight and bare-bone, and this makes them very reliable and precise. In contrast, soft PLCs, or software-based PLCs, run on standard industrial PCs and standard operating systems such as Linux. These standard operating systems are not designed for real-time operations, nor are they as reliable, so soft PLCs simply could not match the performance of hard PLCs.
Performance and versatility, the key to Industry 4.0
But this is changing. As modern hardware and software keep getting better, there is a new breed of soft PLCs, often called software-defined controllers, that run on real-time operating systems and have performance catching up to that of hard PLCs. However, if this is the only improvement, then it would still be an uphill battle for market share.
The real shift in the use of soft PLCs is Industry 4.0. More companies are seeking to implement a modern industrial automation system that is connected, data-driven and intelligent. While hard PLCs are good at control, the increasing demand for data and security, both essential components of Industry 4.0, call for the shift to soft PLCs.
Soft PLCs are more suitable for Industry 4.0 due to its versatility and security features
To understand how soft PLCs are more suitable for Industry 4.0, we can take a look at the architecture of a state-of-the-art software-defined controller system - the ctrlX CORE from Bosch Rexroth.
- At the hardware level, the ctrlX CORE runs on a 64-bit Quad-CORE ARM CPU, and it provides 4GB of eMMC storage and 2GB of RAM.
- At the software level, it runs a real-time Linux operating system capable of supporting containers. Containerized applications are isolated from each other, but can talk to each other via a common data layer.
From a versatility perspective, the ctrlX CORE is much more than a PLC. On top of the PLC app, it also includes motion, IoT, and supports third-party apps. This expands the capability of the ctrlX CORE to support applications such as HMI, IoT, machine vision, and machine learning.
The ctrlX CORE also meets the need for strong security features. Standard operating systems are battle-tested in networked environments and support advanced security features like certificate-based authentication, advanced encryption, and role-based permissions. This helps soft PLCs shine whereas traditional PLCs often lag behind in Industry 4.0 security.
Soft PLC is taking off
Whether companies want to hold on to hard PLCs for its familiarity and reliability, or to keep an open mind of what soft PLCs have to offer, PLCs are evolving. Just like how software and operating systems played a role in transforming the handheld mobile phone into the smartphones that have grown to become an essential part of many people's lives today, the PLC is also transforming from being a programmable controller to becoming an intelligent computing device to Industry 4.0 applications. This may still take some time, but the shift is already happening.
Conquer the complexity of IoT
Learn how to navigate the rapid data growth and complexity of IoT adoption. Download white paper.