RAS_FLOW_CTRL
Return-activated-sludge ratio control with a bounded clarifier-blanket trim, rate limiting and a fallback flow on loss of the influent meter.
When to use it
Use RAS_FLOW_CTRL when return activated sludge is paced as a ratio of the influent or plant flow, and the return rate may be trimmed within a bounded band from the final clarifier's sludge blanket.
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 | — |
| INF_FLOW | REAL | m3/h |
| FLOW_OK | BOOL | — |
| RATIO_PCT | REAL | % |
| RAS_MIN | REAL | m3/h |
| RAS_MAX | REAL | m3/h |
| RAS_FAIL | REAL | m3/h |
| RATE_LIM | REAL | m3/h/min |
| BLANKET_M | REAL | m |
| BLANKET_OK | BOOL | — |
| BLANKET_SP_M | REAL | m |
| TRIM_EN | BOOL | — |
| TRIM_GAIN | REAL | %/m/min |
| TRIM_MAX_PCT | REAL | % |
| RAS_FLOW_MEAS | REAL | m3/h |
| RAS_MEAS_OK | BOOL | — |
| DEV_M3H | REAL | m3/h |
| DEV_T | TIME | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| RAS_SP | REAL | m3/h |
| RATIO_ACTUAL_PCT | REAL | % |
| TRIM_PCT | REAL | % |
| VALID | BOOL | — |
| AT_LIMIT | BOOL | — |
| ALM_FLOW_FAULT | BOOL | — |
| ALM_BLANKET_FAULT | BOOL | — |
| ALM_RAS_DEV | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 8
- Simulated scans
- 959
- 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 RAS_FLOW_CTRL — free
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