STDDEV_WIN
Windowed standard deviation by the two-pass method, with the window mean published alongside.
When to use it
Use STDDEV_WIN when the variability of a signal is the diagnostic — a control loop that is hunting, a chiller short-cycling, a flow meter starting to cavitate, a charger current that has become ragged — and a number is wanted for the noise itself rather than for the level.
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 | — |
| SAMPLE_SD | BOOL | — |
| SAMPLE_T | TIME | — |
| RESET | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| OUT | REAL | EU |
| MEAN | REAL | EU |
| VALID | BOOL | — |
| N_VALID | UINT | — |
| ALM_SIG_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
| ALM_UNDERSAMPLED | BOOL | — |
Validation evidence
- Tests
- 7
- Simulated scans
- 65
- 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 STDDEV_WIN — free
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