Overview

taktora-executor is a Rust execution framework on iceoryx2 that turns IPC events, intervals, and request/response activity into deterministic, observable schedules of executable items.

This specification frames taktora-executor as the runtime heart of a soft-real-time PLC: a foundation for non-safety industrial automation, robotics control loops, machine-monitoring runtimes, and R&D testbeds where occasional jitter is acceptable. The framing follows directly from a gap analysis (recorded in Soft-RT PLC runtime heart) that distinguishes the capabilities taktora-executor already provides from those that must be added before it can credibly call itself a soft-RT PLC.

What is out of scope for the runtime heart:

  • Hard-real-time guarantees (cycle deadlines bounded to microsecond jitter under any load).

  • IEC 61508 / 26262 functional safety certification or SIL / ASIL claims.

  • IEC 61131-3 frontends (ladder logic, function block diagram, structured text).

  • Hot-standby, redundancy, online change.

  • Specific fieldbus protocols (EtherCAT, Modbus, Profinet, CIP); only the integration interface is in scope.

This document is structured as engineering artefacts. Top-level capabilities are feat directives; individual obligations are req directives that :satisfies: their parent feature. Every artefact carries a stable ID (FEAT_NNNN, REQ_NNNN) and a lifecycle :status:.

Reading order

Start with Soft-RT PLC runtime heart for the full feature/requirement decomposition. Work-in-progress sections — Architecture and Verification — will land alongside the implementation work that closes the gap requirements.

Status legend

  • open — drafted; not yet reviewed.

  • draft — under active authoring (used during edits).

  • reviewed — passed at least one structured review.

  • approved — accepted into the baseline.

All artefacts in this initial drop are authored at open until they are reviewed; the status lifecycle is honest about provenance rather than optimistic.