ANOMALY_ZSCORE
Z-score anomaly detector scored against the preceding window, with a held baseline and a floor under sigma.
When to use it
Use ANOMALY_ZSCORE when a signal has no fixed alarm limits but a characteristic behaviour — a pump's power draw at a given duty, a chiller's approach temperature, a charger's session current, a filter's differential pressure — and what matters is a sample that is unlike the recent past rather than a sample that crosses a number.
Interface
The published port signature. This is the whole of what the block exposes to your program — the implementation body is not shown here and ships with the download.
Inputs
| Port | Type | Unit |
|---|---|---|
| IN | REAL | EU |
| IN_OK | BOOL | — |
| WINDOW | UINT | — |
| Z_LIMIT | REAL | sigma |
| SIGMA_MIN | REAL | EU |
| HOLD_BASELINE | BOOL | — |
| SAMPLE_T | TIME | — |
| RESET | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| Z | REAL | sigma |
| ANOM | BOOL | — |
| ALM_ANOM | BOOL | — |
| ANOM_RUN | UINT | — |
| MU | REAL | EU |
| SIGMA | REAL | EU |
| VALID | BOOL | — |
| N_VALID | UINT | — |
| ALM_SIG_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
| ALM_UNDERSAMPLED | BOOL | — |
Validation evidence
- Tests
- 8
- Simulated scans
- 121
- Simulator
- v0.1.0
Complete IEC 61131-3 implementation with a published test suite that runs on the vplant simulator. The counts above are that suite, executed on this build.
- Conforms to IEC 61131-3
Download ANOMALY_ZSCORE — free
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