BE1_81_FREQ
Basler-shaped under / over-frequency element (ANSI 81) with definite-time delay, reset hysteresis, plausibility blocking and an optional rate-of-change stage.
When to use it
Use BE1_81_FREQ when a generator, an intertie or a load-shedding stage must act on grid frequency excursions, and the element must not act on a frequency measurement taken from a collapsed or absent voltage.
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 |
|---|---|---|
| ENABLE | BOOL | — |
| f | REAL | Hz |
| fset | REAL | Hz |
| fOset | REAL | Hz |
| df | REAL | Hz/s |
| tD | TIME | — |
| F_HYST | REAL | Hz |
| DFDT_EN | BOOL | — |
| DFDT_SET | REAL | Hz/s |
| TD_ROC | TIME | — |
| F_MIN | REAL | Hz |
| F_MAX | REAL | Hz |
| F_OK | BOOL | — |
| UV_INH | BOOL | — |
| BLK | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type |
|---|---|
| TRIP | BOOL |
| UF | BOOL |
| OVF | BOOL |
| ROCOF_TRIP | BOOL |
| BLOCKED | BOOL |
| ALM_F_FAIL | BOOL |
| ALM_CFG_ERR | BOOL |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
BE1_81_FREQ commands a real actuator. It is written to sit underneath your own interlock, permissive and protection logic — not to replace it. Commission it as you would any control block you wrote yourself.
Validation evidence
- Tests
- 11
- Simulated scans
- 197
- 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
- Conforms to IEC 61499
Download BE1_81_FREQ — free
Create a free Ri Tech account to download the block. You get the Structured Text body, the Rockwell Add-On Instruction (.L5X), the Schneider Control Expert DFB (.XDB), PLCopen XML, the IEC 61499 function block type (.fbt) and the datasheet.
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Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.