FA-91861 / PLC ladder logic scan cycles / Open access
TON timing bit stays on after the delay completes · case 01
TT and DN are both true on the same scan once the timer has finished.
ROOT CAUSE
TT is driven only by the rung condition and ignores the done state.
THE FAILURE
TT is driven only by the rung condition and ignores the done state.
Unsuccessful approach: Deriving TT from DN alone reports timing on scans where the rung is false.
Case contract
On-delay timer (TON) evaluated once per scan. scans is a list of [rung_in, elapsed_ms since the previous scan]. The accumulator starts on the false-to-true scan without crediting that scan's elapsed time, then adds each later true scan's elapsed time, clamped at preset. A false rung resets the accumulator. DN is rung_in and acc >= preset; TT is rung_in and not DN. Return [DN, TT, ACC] per scan.
Why this case matters
Ladder programs are executed as repeated scans; each defect here changes what a rung, timer, counter or data-table instruction reports on a particular scan, which is how commissioning and field faults are actually observed.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(preset, scans):
acc = 0
prev = False
out = []
for rung_in, dt in scans:
rung_in = bool(rung_in)
if rung_in and prev:
acc = min(preset, acc + dt)
elif not rung_in:
acc = 0
dn = rung_in and acc >= preset
tt = rung_in
prev = rung_in
out.append([dn, tt, acc])
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 1',
[30, [[True, 40], [False, 75], [True, 60], [False, 25], [False, 10], [True, 60], [True, 25], [True, 40]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[True, False, 30]]],
['regression: scenario 2',
[30, [[False, 25], [True, 50], [True, 0], [True, 0], [True, 25], [True, 75], [True, 75]]],
[[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 0],
[False, True, 25],
[True, False, 30],
[True, False, 30]]],
['regression: scenario 3',
[120, [[True, 25], [True, 20], [False, 75], [True, 75], [True, 0], [False, 10], [True, 25]]],
[[False, True, 0],
[False, True, 20],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0]]],
['regression: scenario 4',
[0,
[[True, 10],
[False, 25],
[True, 25],
[True, 20],
[True, 40],
[True, 20],
[True, 75],
[True, 0],
[True, 10]]],
[[True, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0]]]],
[['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[0,
[[True, 40],
[True, 10],
[True, 10],
[False, 10],
[True, 20],
[True, 25],
[True, 20],
[False, 25],
[True, 20]]],
[[True, False, 0],
[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0]]],
['regression: scenario 2',
[150,
[[True, 60],
[True, 10],
[False, 20],
[False, 40],
[True, 50],
[True, 25],
[False, 25],
[False, 75],
[True, 25],
[False, 0],
[True, 60],
[False, 10]]],
[[False, True, 0],
[False, True, 10],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 3',
[50,
[[False, 50],
[True, 75],
[True, 75],
[True, 20],
[True, 75],
[True, 0],
[False, 60],
[True, 25],
[False, 10]]],
[[False, False, 0],
[False, True, 0],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 4',
[120,
[[True, 75],
[False, 60],
[True, 20],
[True, 25],
[False, 40],
[False, 40],
[True, 50],
[True, 60],
[True, 75],
[True, 40],
[True, 0]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 60],
[True, False, 120],
[True, False, 120],
[True, False, 120]]]],
[['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[50,
[[True, 75],
[True, 40],
[True, 60],
[True, 0],
[True, 25],
[False, 50],
[False, 75],
[True, 60],
[True, 20],
[True, 60],
[False, 60],
[True, 75]]],
[[False, True, 0],
[False, True, 40],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[True, False, 50],
[False, False, 0],
[False, True, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[120, [[False, 0], [False, 75], [True, 75], [True, 0], [True, 0], [False, 75], [True, 60], [True, 40]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 40]]],
['regression: scenario 3',
[50,
[[True, 40],
[False, 0],
[True, 60],
[True, 0],
[True, 40],
[True, 0],
[True, 0],
[False, 0],
[False, 50],
[False, 60],
[False, 10],
[True, 60]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 40],
[False, True, 40],
[False, True, 40],
[False, False, 0],
[False, False, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0]]],
['regression: scenario 4',
[100, [[False, 60], [False, 20], [True, 75], [False, 25], [True, 60], [False, 25], [True, 40]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0]]]],
[['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[100, [[False, 50], [True, 50], [True, 20], [False, 50], [True, 40], [True, 10], [False, 10]]],
[[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, False, 0],
[False, True, 0],
[False, True, 10],
[False, False, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[0,
[[True, 10],
[True, 0],
[False, 50],
[True, 40],
[False, 20],
[False, 25],
[True, 50],
[True, 60],
[True, 40]]],
[[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0]]],
['regression: scenario 3',
[120,
[[True, 60],
[True, 10],
[False, 10],
[True, 50],
[True, 20],
[True, 25],
[True, 25],
[False, 75],
[True, 40],
[True, 50],
[True, 75],
[True, 0]]],
[[False, True, 0],
[False, True, 10],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 45],
[False, True, 70],
[False, False, 0],
[False, True, 0],
[False, True, 50],
[True, False, 120],
[True, False, 120]]],
['regression: scenario 4',
[0, [[True, 25], [False, 75], [True, 20], [False, 25], [True, 20], [False, 25], [True, 40]]],
[[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0]]]],
[['regression: scenario 1',
[120,
[[True, 0],
[True, 50],
[True, 50],
[True, 75],
[True, 75],
[False, 40],
[True, 25],
[False, 0],
[False, 10],
[True, 25],
[False, 0]]],
[[False, True, 0],
[False, True, 50],
[False, True, 100],
[True, False, 120],
[True, False, 120],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 3',
[200,
[[False, 20],
[False, 50],
[True, 75],
[False, 60],
[False, 50],
[True, 0],
[True, 25],
[True, 20],
[True, 40],
[True, 25],
[True, 25],
[True, 60]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, True, 45],
[False, True, 85],
[False, True, 110],
[False, True, 135],
[False, True, 195]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[150, [[True, 50], [False, 40], [True, 20], [True, 20], [True, 10], [True, 40], [False, 50]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 30],
[False, True, 70],
[False, False, 0]]],
['regression: scenario 4',
[100,
[[False, 60],
[False, 0],
[True, 50],
[True, 20],
[True, 60],
[True, 20],
[True, 50],
[True, 0],
[True, 20],
[True, 0],
[True, 20],
[True, 25]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 80],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100]]]]]
for label, args, expected in fixtures[N-1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| regression: preset reached exactly | [[False, True, 0], [False, True, 50], [True, True, 100], [True, True, 100]] | [[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]] | Failed |
| regression: zero preset | [[False, False, 0], [True, True, 0], [False, False, 0], [True, True, 0]] | [[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]] | Failed |
| regression: interrupted timing restarts | [[False, True, 0], [False, True, 40], [False, False, 0], [False, True, 0], [False, True, 40], [True, True, 60]] | [[False, True, 0], [False, True, 40], [False, False, 0], [False, True, 0], [False, True, 40], [True, False, 60]] | Failed |
| regression: long hold after done | [[False, True, 0], [False, True, 30], [True, True, 50], [True, True, 50], [False, False, 0]] | [[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]] | Failed |
| regression: scenario 1 | [[False, True, 0], [False, False, 0], [False, True, 0], [False, False, 0], [False, False, 0], [False, True, 0], [False, True, 25], [True, True, 30]] | [[False, True, 0], [False, False, 0], [False, True, 0], [False, False, 0], [False, False, 0], [False, True, 0], [False, True, 25], [True, False, 30]] | Failed |
| regression: scenario 2 | [[False, False, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 25], [True, True, 30], [True, True, 30]] | [[False, False, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 25], [True, False, 30], [True, False, 30]] | Failed |
| regression: scenario 3 | [[False, True, 0], [False, True, 20], [False, False, 0], [False, True, 0], [False, True, 0], [False, False, 0], [False, True, 0]] | [[False, True, 0], [False, True, 20], [False, False, 0], [False, True, 0], [False, True, 0], [False, False, 0], [False, True, 0]] | Passed |
| regression: scenario 4 | [[True, True, 0], [False, False, 0], [True, True, 0], [True, True, 0], [True, True, 0], [True, True, 0], [True, True, 0], [True, True, 0], [True, True, 0]] | [[True, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0]] | Failed |
SHA-256 / 72160f79859883c63ad5add66f8f583bf122395873678faabefea9afa2764e93
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(preset, scans):
acc = 0
prev = False
out = []
for rung_in, dt in scans:
rung_in = bool(rung_in)
if rung_in and prev:
acc = min(preset, acc + dt)
elif not rung_in:
acc = 0
dn = rung_in and acc >= preset
tt = not dn
prev = rung_in
out.append([dn, tt, acc])
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 1',
[30, [[True, 40], [False, 75], [True, 60], [False, 25], [False, 10], [True, 60], [True, 25], [True, 40]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[True, False, 30]]],
['regression: scenario 2',
[30, [[False, 25], [True, 50], [True, 0], [True, 0], [True, 25], [True, 75], [True, 75]]],
[[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 0],
[False, True, 25],
[True, False, 30],
[True, False, 30]]],
['regression: scenario 3',
[120, [[True, 25], [True, 20], [False, 75], [True, 75], [True, 0], [False, 10], [True, 25]]],
[[False, True, 0],
[False, True, 20],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0]]],
['regression: scenario 4',
[0,
[[True, 10],
[False, 25],
[True, 25],
[True, 20],
[True, 40],
[True, 20],
[True, 75],
[True, 0],
[True, 10]]],
[[True, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0]]]],
[['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[0,
[[True, 40],
[True, 10],
[True, 10],
[False, 10],
[True, 20],
[True, 25],
[True, 20],
[False, 25],
[True, 20]]],
[[True, False, 0],
[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0]]],
['regression: scenario 2',
[150,
[[True, 60],
[True, 10],
[False, 20],
[False, 40],
[True, 50],
[True, 25],
[False, 25],
[False, 75],
[True, 25],
[False, 0],
[True, 60],
[False, 10]]],
[[False, True, 0],
[False, True, 10],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 3',
[50,
[[False, 50],
[True, 75],
[True, 75],
[True, 20],
[True, 75],
[True, 0],
[False, 60],
[True, 25],
[False, 10]]],
[[False, False, 0],
[False, True, 0],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 4',
[120,
[[True, 75],
[False, 60],
[True, 20],
[True, 25],
[False, 40],
[False, 40],
[True, 50],
[True, 60],
[True, 75],
[True, 40],
[True, 0]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 60],
[True, False, 120],
[True, False, 120],
[True, False, 120]]]],
[['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[50,
[[True, 75],
[True, 40],
[True, 60],
[True, 0],
[True, 25],
[False, 50],
[False, 75],
[True, 60],
[True, 20],
[True, 60],
[False, 60],
[True, 75]]],
[[False, True, 0],
[False, True, 40],
[True, False, 50],
[True, False, 50],
[True, False, 50],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[True, False, 50],
[False, False, 0],
[False, True, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[120, [[False, 0], [False, 75], [True, 75], [True, 0], [True, 0], [False, 75], [True, 60], [True, 40]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 40]]],
['regression: scenario 3',
[50,
[[True, 40],
[False, 0],
[True, 60],
[True, 0],
[True, 40],
[True, 0],
[True, 0],
[False, 0],
[False, 50],
[False, 60],
[False, 10],
[True, 60]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 0],
[False, True, 40],
[False, True, 40],
[False, True, 40],
[False, False, 0],
[False, False, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0]]],
['regression: scenario 4',
[100, [[False, 60], [False, 20], [True, 75], [False, 25], [True, 60], [False, 25], [True, 40]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, True, 0]]]],
[['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[100, [[False, 50], [True, 50], [True, 20], [False, 50], [True, 40], [True, 10], [False, 10]]],
[[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, False, 0],
[False, True, 0],
[False, True, 10],
[False, False, 0]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: scenario 1',
[0,
[[True, 10],
[True, 0],
[False, 50],
[True, 40],
[False, 20],
[False, 25],
[True, 50],
[True, 60],
[True, 40]]],
[[True, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[False, False, 0],
[True, False, 0],
[True, False, 0],
[True, False, 0]]],
['regression: scenario 3',
[120,
[[True, 60],
[True, 10],
[False, 10],
[True, 50],
[True, 20],
[True, 25],
[True, 25],
[False, 75],
[True, 40],
[True, 50],
[True, 75],
[True, 0]]],
[[False, True, 0],
[False, True, 10],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 45],
[False, True, 70],
[False, False, 0],
[False, True, 0],
[False, True, 50],
[True, False, 120],
[True, False, 120]]],
['regression: scenario 4',
[0, [[True, 25], [False, 75], [True, 20], [False, 25], [True, 20], [False, 25], [True, 40]]],
[[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0],
[False, False, 0],
[True, False, 0]]]],
[['regression: scenario 1',
[120,
[[True, 0],
[True, 50],
[True, 50],
[True, 75],
[True, 75],
[False, 40],
[True, 25],
[False, 0],
[False, 10],
[True, 25],
[False, 0]]],
[[False, True, 0],
[False, True, 50],
[False, True, 100],
[True, False, 120],
[True, False, 120],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0]]],
['regression: scenario 3',
[200,
[[False, 20],
[False, 50],
[True, 75],
[False, 60],
[False, 50],
[True, 0],
[True, 25],
[True, 20],
[True, 40],
[True, 25],
[True, 25],
[True, 60]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 25],
[False, True, 45],
[False, True, 85],
[False, True, 110],
[False, True, 135],
[False, True, 195]]],
['regression: preset reached exactly',
[100, [[True, 30], [True, 50], [True, 50], [True, 10]]],
[[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]]],
['regression: zero preset',
[0, [[False, 10], [True, 10], [False, 5], [True, 40]]],
[[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]]],
['regression: interrupted timing restarts',
[60, [[True, 40], [True, 40], [False, 40], [True, 40], [True, 40], [True, 40]]],
[[False, True, 0],
[False, True, 40],
[False, False, 0],
[False, True, 0],
[False, True, 40],
[True, False, 60]]],
['regression: long hold after done',
[50, [[True, 30], [True, 30], [True, 30], [True, 30], [False, 30]]],
[[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]]],
['regression: scenario 2',
[150, [[True, 50], [False, 40], [True, 20], [True, 20], [True, 10], [True, 40], [False, 50]]],
[[False, True, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 30],
[False, True, 70],
[False, False, 0]]],
['regression: scenario 4',
[100,
[[False, 60],
[False, 0],
[True, 50],
[True, 20],
[True, 60],
[True, 20],
[True, 50],
[True, 0],
[True, 20],
[True, 0],
[True, 20],
[True, 25]]],
[[False, False, 0],
[False, False, 0],
[False, True, 0],
[False, True, 20],
[False, True, 80],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100],
[True, False, 100]]]]]
for label, args, expected in fixtures[N-1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| regression: preset reached exactly | [[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]] | [[False, True, 0], [False, True, 50], [True, False, 100], [True, False, 100]] | Passed |
| regression: zero preset | [[False, True, 0], [True, False, 0], [False, True, 0], [True, False, 0]] | [[False, False, 0], [True, False, 0], [False, False, 0], [True, False, 0]] | Failed |
| regression: interrupted timing restarts | [[False, True, 0], [False, True, 40], [False, True, 0], [False, True, 0], [False, True, 40], [True, False, 60]] | [[False, True, 0], [False, True, 40], [False, False, 0], [False, True, 0], [False, True, 40], [True, False, 60]] | Failed |
| regression: long hold after done | [[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, True, 0]] | [[False, True, 0], [False, True, 30], [True, False, 50], [True, False, 50], [False, False, 0]] | Failed |
| regression: scenario 1 | [[False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 25], [True, False, 30]] | [[False, True, 0], [False, False, 0], [False, True, 0], [False, False, 0], [False, False, 0], [False, True, 0], [False, True, 25], [True, False, 30]] | Failed |
| regression: scenario 2 | [[False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 25], [True, False, 30], [True, False, 30]] | [[False, False, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 25], [True, False, 30], [True, False, 30]] | Failed |
| regression: scenario 3 | [[False, True, 0], [False, True, 20], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0], [False, True, 0]] | [[False, True, 0], [False, True, 20], [False, False, 0], [False, True, 0], [False, True, 0], [False, False, 0], [False, True, 0]] | Failed |
| regression: scenario 4 | [[True, False, 0], [False, True, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0]] | [[True, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0]] | Failed |
SHA-256 / 610b20d6253a33096c806ff167224c9e06346c075e30674e87cf187562722d1e
HELD IN THE MEMBER ARCHIVE
The verified repair and its recorded checks are member-only.
This mechanism has 8 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.
Sign in to the archive ↗Verification & scope
A deterministic bounded teaching model of one PLC instruction or rung pattern evaluated scan by scan. The stated contract is a stipulated toy convention, not a claim of conformance to any vendor controller or IEC 61131-3 runtime. 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 2026-09-29T14:51:40.188581+00:00.
Case digest / 162d30396df76011eaf166ed6dc399f2501c0d8527ea0a52ace8d52298f65505