The brains of industry are industrial computers. They operate similarly to PLCs in that they take inputs, generate outputs, and regulate automation. So what distinguishes automation control by an industrial computer from automation control by a PLC?
Connections and Interfaces
Although a PLC provides a large range of I/O possibilities, it is typically limited in scope. A larger variety of external devices, including monitors, drivers, printers, network interface cards, and peripherals from various manufacturers, can be connected to an industrial PC.
An industrial PC can be customized and expanded as needed thanks to its various I/O and card ports. An HMI, a vision system, or wireless or cellular cards, for instance, can all be supported by an industrial PC. But in order to take the position of a PLC, an industrial PC will require the right software stack.
PLCs use ladder logic or other specialized programming languages, such as structured text or function block diagram, for programming. These languages are designed to represent and control discrete and analog signals commonly found in industrial systems.
Industrial computers generally use standard programming languages like C++, Java, or Python. They offer greater flexibility for software development and can run various operating systems, including Windows, Linux, or real-time operating systems.
Storage and efficiency
When compared to PLCs, industrial PCs perform better in terms of CPU performance and storage capacity. This can be helpful for complex scenario programming flexibility, data analysis capabilities, data storage (logging), and integration of artificial intelligence and machine learning. Additionally, because workloads may be concentrated and the hardware footprint can be decreased, an industrial PC might be useful in circumstances where there is a lack of space.
The operating system of security PLCs is quite basic and was created specifically for the control task at hand. A hard PLC does not disclose security issues commonly connected with common consumer operating systems because of its simple software programming.
The operating system for an industrial PC must, however, allow it to execute a variety of applications. Could the industrial PC be more susceptible to hacks, you might wonder?
The truth is that modern industrial PCs are built with extensive security-related features. Additionally, since PCs are so common, vulnerabilities and exploitations are frequently found early on and stopped. PLCs, on the other hand, undergo updates less regularly, and because they use outdated technology, this could result in a less secure installation as a whole.
There are no significant differences in terms of resistance to environmental conditions because we are comparing PLCs to industrial computers rather than traditional PCs. PLCs were created to function in the very challenging settings of industrial facilities, just like industrial PCs.
Determinism and Real-time Performance
PLCs are designed for real-time control applications and offer deterministic operation, meaning they execute control logic predictably and with precise timing. They prioritize the execution of control tasks over other system processes.
While industrial computers can be used in real-time applications, their performance may not be as deterministic as PLCs. Factors like operating system tasks, background processes, and hardware capabilities can affect their real-time response.
Redundancy and Fault Tolerance
PLCs often support built-in redundancy features, such as hot-swappable modules and redundant power supplies, to enhance system availability and fault tolerance. These features are crucial in critical industrial applications.
Industrial computers may offer redundancy options, but they typically require additional hardware and software configurations to achieve fault tolerance. It is less common to find the same level of built-in redundancy as in PLCs.
Installing an industrial computer in place of a PLC
A programmable logic controller (PLC) might be more appropriate and cost-effective for smaller projects. An industrial PC, however, might be more appropriate and provide a higher return on investment (ROI) for projects that may be expanded in the future. In the end, the choice between a programmable logic controller (PLC) and an industrial PC (IPC) is determined by the specific application