FA-11976 / Discrete control systems / Open access

A blocked switching request restarts the dwell timer · case 01

A blocked switching request restarts the dwell timer.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Elapsed time is measured from every request rather than the last accepted switch.

THE FAILURE

Elapsed time is measured from every request rather than the last accepted switch.

Unsuccessful approach: Updating the timestamp on redundant requests also delays later legitimate switches.

Case contract

State is (on,last_switch). At integer now>=last_switch, accept a different desired state iff now-last_switch>=dwell; redundant or blocked requests preserve both fields.

Why this case matters

An offline discrete controller model isolates this state or arithmetic fault; it makes no physical plant or safety claim.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(on, last, desired, now, dwell):
    return [desired if now-last>=dwell else on, now]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('blocked request', solve(False, N, True, N+1, 3), [False,N])
check('redundant late', solve(False, N, False, N+5, 3), [False,N])
check('exact dwell', solve(False, N, True, N+3, 3), [True,N+3])
check('switch off', solve(True, N, False, N+4, 3), [False,N+4])
check('zero dwell', solve(False, N, True, N, 0), [True,N])
check('same instant unchanged', solve(True, N, True, N, 0), [True,N])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
blocked request	`[False, 2]`	`[False, 1]`	Failed
redundant late	`[False, 6]`	`[False, 1]`	Failed
exact dwell	`[True, 4]`	`[True, 4]`	Passed
switch off	`[False, 5]`	`[False, 5]`	Passed
zero dwell	`[True, 1]`	`[True, 1]`	Passed
same instant unchanged	`[True, 1]`	`[True, 1]`	Passed

SHA-256 / 1ae2e94ae0afcae17c2c69f124fea264f2d8b1e813bd615f7b6b6655956414d7

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(on, last, desired, now, dwell):
    return [desired if now-last>=dwell else on, now if desired==on or now-last>=dwell else last]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('blocked request', solve(False, N, True, N+1, 3), [False,N])
check('redundant late', solve(False, N, False, N+5, 3), [False,N])
check('exact dwell', solve(False, N, True, N+3, 3), [True,N+3])
check('switch off', solve(True, N, False, N+4, 3), [False,N+4])
check('zero dwell', solve(False, N, True, N, 0), [True,N])
check('same instant unchanged', solve(True, N, True, N, 0), [True,N])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
blocked request	`[False, 1]`	`[False, 1]`	Passed
redundant late	`[False, 6]`	`[False, 1]`	Failed
exact dwell	`[True, 4]`	`[True, 4]`	Passed
switch off	`[False, 5]`	`[False, 5]`	Passed
zero dwell	`[True, 1]`	`[True, 1]`	Passed
same instant unchanged	`[True, 1]`	`[True, 1]`	Passed

SHA-256 / ebb8d8eb889fae1f8509de56f63cc58a331cd70ee49fe3dc72c5423d53ed474d

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Integer-valued controlled examples only; no physical plant, stability guarantee, timing jitter, or hardware behavior is modeled. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:52.743138+00:00.

Case digest / 06065b39bcf974901ea88d625e335426b83472eea0710a6d94b5d35b64fd2282