OPC UA PubSub Timing Budget Calculator (IEC 62541-8 compliant)

The calculator operationalizes the timing model defined in IEC 62541-8 Annex A and aligns with ISO/IEC/IEEE 29113 (real-time interoperability) and IEC 61784-2 (CPF 17 for time-sensitive networking). It decomposes the total allowable end-to-end latency (T_max) into deterministic and probabilistic components—such as publisher processing time (T_pub), network propagation delay (T_prop), switch forwarding latency (T_sw), subscriber processing time (T_sub), and worst-case jitter (T_jitter)—while accounting for synchronization accuracy (e.g., IEEE 1588 PTP class), message size, MTU, and underlying transport characteristics (e.g., UDP vs. TSN-aware Ethernet). Each component is parameterized with conservative vendor- or hardware-specific bounds (e.g., microsecond-level NIC interrupt latency, FPGA-based encoder overhead), enabling traceable budget allocation per information flow (e.g., safety-critical alarm vs. non-critical telemetry). Crucially, the tool integrates energy-aware parameters—such as sleep/wake transition times, low-power mode activation delays, and duty-cycle-induced latency penalties—allowing designers to evaluate trade-offs between timing predictability and power consumption in battery-operated or thermally constrained edge devices. Validation outputs include slack time analysis, critical path identification, and compliance reports against user-defined SLAs (e.g., <100 μs cycle time at 99.999% reliability), supporting certification under functional safety standards like IEC 61508 or ISO 13849 when combined with appropriate hardware assurance.