PERMIT_LIMIT_GUARD
Discharge-permit guard: headroom reporting, approach warning, confirmed trip to divert or recirculate, and excursion accounting.
When to use it
Use PERMIT_LIMIT_GUARD when a consented parameter is measured continuously on a discharge and the works can divert or recirculate rather than breach — the final-effluent ammonia, phosphate, turbidity, conductivity or residual-chlorine guard.
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 | — |
| PV | REAL | mg/L |
| PV_OK | BOOL | — |
| WARN | REAL | mg/L |
| LIMIT | REAL | mg/L |
| DELAY | TIME | — |
| RESET_DB | REAL | mg/L |
| MIN_DIVERT_T | TIME | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| MARGIN_PCT | REAL | % |
| DIVERT_CMD | BOOL | — |
| COMPLIANT | BOOL | — |
| VALID | BOOL | — |
| ALM_WARN | BOOL | — |
| ALM_TRIP | BOOL | — |
| ALM_PV_FAULT | BOOL | — |
| EXCEED_S | REAL | s |
| EXCEED_COUNT | DINT | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
PERMIT_LIMIT_GUARD 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
- 9
- Simulated scans
- 244
- 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 PERMIT_LIMIT_GUARD — 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.
Every block in the catalogue is free to download, in every format, with no purchase and no card. Browsing needs no account at all; downloading needs a signed-in one, so the block lands in your library and re-downloads whenever you need it.
Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.