Dynamic protection state is preserved
The runtime does not clear timers merely because a forward communication discontinuity occurred. Trust policy determines whether a new operation can be asserted.
Ingress decision
Counter behavior is classified before measurement admission.
| Observed counter relation | Decision | Payload consequence | Evidence consequence |
|---|---|---|---|
Expected next smpCnt | Accept | Samples may enter the runtime pipeline | Normal continuity state |
| Same as last accepted | Drop duplicate | Payload rejected before measurement | Duplicate counter and notice retained |
| Backward / old counter | Drop out of order | Payload rejected before measurement | Ordering telemetry retained |
| Forward discontinuity | Restart window | Post-gap samples rebuild contiguous windows | Gap and recovery state retained |
Continuity model
Modulo arithmetic distinguishes wrap, forward gaps, and backward frames.
The gate derives the expected next counter from the last accepted counter and the resolved wrap value. A forward displacement smaller than half the wrap is treated as a gap/restart; a backward displacement is rejected as out of order.
expected = (previous + 1) mod wrap current == expected → accept current == previous → drop duplicate forward < wrap / 2 → restart contiguous window otherwise → drop out of order
Scope: this classification is continuity evidence for the current stream identity. It is not a network-wide time-synchronization or publisher-health certification.
State preservation
A communication gap does not silently erase protection history.
Existing trip evidence remains latched
A previously latched virtual trip is not automatically erased by a stream gap. Reset remains an explicit operator action.
Last coherent evidence may be held
The UI can retain the last complete waveform and phasor evidence while contiguous post-gap windows rebuild, preventing a partial or mixed window from appearing coherent.
Trust permissions
Visibility, pickup evaluation, and trip authority are distinct.
Key behavior: the automated protection test demonstrates a blocked state in which phase pickup remains visible while a repeated
smpCnt gap prevents the virtual trip latch from asserting.Research questions
Current logic creates a clear baseline for stronger continuity studies.
Validated in the current beta
- Modulo counter progression
- Duplicate rejection
- Out-of-order rejection
- Forward-gap window restart
- Pickup-visible, trip-blocked protection state
- Explicit stream and trust evidence
Future research track
- Loss-burst and jitter sweeps
- Multiple ASDUs per frame under stress
- Cross-stream time alignment
- Publisher restart and
confRevtransition policy - PTP quality and time-error evidence
- Hardware-in-the-loop latency characterization