3o|||sheet Automation

3o|||sheet is a universal software environment for developing applications for Programmable Logic Controllers (PLCs).

• Hardware Independence
• Integrated Development Environment (IDE)

A lightweight, cross-platform IDE built on OpenJDK. Runs on single-board computers with minimal resources.

Supports LD, FBD, and ST languages plus a virtual machine instruction set for advanced logic design.

Offers extensive debugging capabilities: developers can modify code in real-time without physically restarting the PLC.

The development environment can create executable programs for the PLC in two modes:

• Classic PLC mode — cyclic model (OB, OB100). An optimized, economical mode that contains a minimum of additional programs.
• RTOS PLC mode — preemptive multitasking via a 1 ms timer interrupt. In this case, the IDE will additionally install a virtual real-time 3o|||sheet OS to execute tasks in parallel.

Is a standalone application that compiles text programs written in LD, FBD, ST and .3osheet into executable bytecode for a virtual machine.

The compiler can be integrated into third-party development tools (for example, Visual Studio, etc.).

It includes a complete set of tools for working with complex custom variables, virtual stack, and context management, enabling the development of sophisticated recursive algorithms and multithreaded tasks (coroutines).

Register-based Virtual Machine running safely in a sandbox. Works on devices with only 8 KB RAM and full peripheral access.

• Low-memory devices (~8 KB RAM)
• Safe sandboxed execution
• Controls GPIO, timers, UART, I²C, SPI, etc.
• Architecture-independent design

Stack and heap dynamically share a contiguous memory area, allowing flexible memory allocation with minimal overhead.

Execute multiple, hardware-isolated runtime environments on a single MCU. Ensures fault containment and enables functional safety.

The platform incorporates a unique divergent architecture designed for maximum reliability and fault tolerance in safety-critical applications. Divergent Multi-Version Execution (DME) is a redundancy-based fault-tolerance architecture that combines address-space decorrelation with per-instruction full-state hashing. Identical instruction bytes are preserved across replicas, while basic blocks are mapped to distinct virtual addresses. After each instruction, replicas compute incremental architectural state hashes and perform synchronous comparison. The approach targets safety-critical embedded systems, particularly 32-bit microcontrollers (e.g., ARM Cortex-M class). DME reduces the probability of undetected replica-local faults by structurally decorrelating control flow without altering program semantics.