The RevPi Core from KUNBUS GmbH is an industrially hardened programmable logic controller built around the Raspberry Pi Compute Module 4S. It delivers the openness and ease of the Raspberry Pi ecosystem in a DIN-rail mountable format suitable for demanding automation environments. A hardware watchdog, real-time clock with 24-hour backup, and a robust power supply circuit ensure reliable unattended operation.

At its heart lies the Broadcom BCM2711 processor with four ARM Cortex-A72 cores clocked at 1.5 GHz, supported by 1 GB of LPDDR4 RAM. The operating system and application data reside on integrated eMMC memory, available in capacities from 8 GB to 32 GB. This combination of processing power and persistent storage makes the RevPi Core well-suited for edge computing tasks that involve data aggregation, protocol translation, or local decision making.

One of the defining features of the Revolution Pi platform is the PiBridge expansion system. The RevPi Core can host up to 10 additional modules stacked directly on top of the base unit. These modules cover a broad spectrum of functions, from simple digital and analog I/O to specialized gateway modules for PROFINET, EtherNet/IP, or CANopen fieldbuses. The Core S variant supports both I/O and gateway expansion, whereas the Core SE variant provides a cost-effective option limited to I/O modules only.

Industrial resilience is reflected in the power supply design. An internal high-efficiency DC-DC converter accepts input voltages from 10.2 V to 28.8 V, allowing the device to be powered from standard 24 V industrial supplies, batteries, or solar panels. Critically, the RevPi Core can ride through brief power interruptions: it maintains full operation for 10 ms under maximum USB load and for 25 ms with no USB devices connected. This hold-up capability prevents unnecessary restarts during momentary voltage dips.

The software environment offers two parallel development paths. Engineers can use the included logi.CAD 3 environment to create deterministic control programs following the IEC 61131-3 standard, using languages such as Ladder Diagram, Structured Text, or Function Block Diagram. Simultaneously, the underlying Linux operating system with a real-time kernel patch permits the execution of custom applications written in Python, C++, Node-RED, or virtually any Linux-compatible language. The PiCtory configuration tool provides a graphical interface for assigning I/O modules and setting system parameters without manual file editing.

Applications

The RevPi Core is deployed in numerous industrial scenarios, including:

• IIoT gateways that collect machine data and forward it to cloud platforms.
• Modular machine controls requiring distributed I/O and flexible logic.
• Retrofit projects that add modern networking to legacy equipment.
• Building management systems for lighting, HVAC, and access control.
• Test stands and laboratory automation where open software is essential.

Technical Specifications