What Is a Virtual PLC?
A virtual PLC (also called a soft PLC) is a software-based programmable logic controller that runs on general-purpose computing hardware instead of dedicated proprietary controller hardware. Rather than a fixed-function industrial controller, the "PLC" becomes an application — typically built on a real-time runtime such as CODESYS, Siemens SIMATIC S7-1500V, Beckhoff TwinCAT, Rockwell's soft control options, or open-source stacks like OpenPLC — executing on a standard x86 or ARM computer.
This architecture is increasingly common in modern automation. It lets engineers deploy, version and update control logic the same way they manage other software, run multiple virtual controllers on one machine, and consolidate HMI, SCADA gateway, historian and edge analytics functions onto a single device. Because the control logic is decoupled from the hardware, capacity can be scaled by moving to a faster processor or adding memory rather than replacing a proprietary controller.
Hardware Requirements for Soft PLC Deployments
A virtual PLC needs more than raw speed — it needs deterministic behaviour. The key requirements are:
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Consistent, low-latency CPU response. Jitter, not average throughput, determines scan-cycle stability. Fewer background processes and stable thermals matter more than peak clock speed.
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Sufficient RAM. 8 GB is a practical minimum for a single runtime plus HMI; 16 GB or more is comfortable when hosting multiple runtimes, a database or vision/analytics workloads alongside control logic.
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Reliable solid-state storage. Industrial environments see vibration, dust and temperature swings that mechanical drives handle poorly. SSD storage from 128 GB upward covers most runtime, log and recipe needs.
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Wired networking. Control traffic should never depend on WiFi. Dual Gigabit Ethernet ports are valuable for separating the control network from the plant/supervisory network.
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Fanless, sealed cooling. Moving air means moving dust. Fanless designs remove the single most common mechanical failure point and suit cabinets, panels and dusty plant floors.
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Wide-temperature tolerance and stable power. A 12 V DC input and industrial-grade components keep behaviour predictable across shifts and seasons.
Typical Use Cases
Virtual PLCs are used in machine control, packaging and material handling, building automation, water and energy monitoring, and as edge gateways that translate between field protocols (Modbus, OPC UA, EtherCAT, PROFINET) and higher-level systems. They are also popular in test benches, training labs and pilot lines, where engineers can prototype control logic on commodity hardware before committing to a production controller. In retrofit projects, a soft PLC on a small industrial computer can replace or supplement legacy control hardware while keeping existing I/O and field wiring intact.
Matching Hardware to Workload
| Deployment | Suggested CPU class | RAM | Storage | Notes |
|---|---|---|---|---|
| Single soft PLC runtime + basic HMI | Intel Celeron / N-series, 4 cores | 8–16 GB | 128 GB SSD | Fanless mini PC, single Ethernet acceptable |
| Multiple runtimes + SCADA gateway | Intel Core i3 / i5, 6–10 cores | 16–32 GB | 256–512 GB SSD | Dual Ethernet strongly preferred |
| Control + vision or edge analytics | Intel Core i5, 10–12 cores | 32–64 GB | 512 GB–1 TB SSD | Higher thermal headroom, active or high-capacity passive cooling |
Real-time performance also depends on the OS and runtime configuration. Bare-metal Linux with a PREEMPT_RT kernel, or a Windows installation with a dedicated real-time core, generally delivers tighter jitter than a heavily loaded general-purpose desktop OS. Whichever path you choose, disable power-saving states, pin the runtime to dedicated cores where supported, and validate scan-cycle jitter under your actual load before commissioning.
Thinvent Products for Virtual PLC and Soft PLC Applications
Thinvent builds fanless mini PCs, industrial computers and thin clients designed for exactly this class of workload — always-on, dust-exposed, cabinet-mounted control and edge computing. Configurations pair Intel Celeron and N-series processors with 4–64 GB of DDR4 memory and 128 GB–1 TB of SSD storage, with dual Gigabit Ethernet options for separating control and supervisory networks, HDMI output for local HMI, and USB 3.2 Gen 2 and USB-C connectivity for commissioning and peripherals.
Operating system options include Windows 11 Pro, Windows 11 IoT, Ubuntu Linux 24.04 LTS and Thinvent's own Thinux embedded Linux, so you can match the platform to your chosen soft PLC runtime. Sealed fanless chassis, 12 V DC input and no reliance on WiFi make them well suited to panel and plant-floor installation. If you are sizing hardware for a virtual PLC project, Thinvent's team can help match processor, memory and network configuration to your scan-cycle and I/O requirements.
