MLSS_MON
Mixed-liquor suspended-solids analyser front end with band alarms, basin solids inventory and a wasting inhibit on lost measurement.
When to use it
Use MLSS_MON when an optical or ultrasonic MLSS analyser measures the mixed liquor in an aeration basin, and its reading is used to compute solids inventory or to drive sludge wasting.
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 | — |
| MLSS_RAW | REAL | mg/L |
| MLSS_OK | BOOL | — |
| RANGE_MIN | REAL | mg/L |
| RANGE_MAX | REAL | mg/L |
| FILTER_T | TIME | — |
| LOW_LIMIT | REAL | mg/L |
| HIGH_LIMIT | REAL | mg/L |
| LIMIT_HYST | REAL | mg/L |
| VOLUME_M3 | REAL | m3 |
| FREEZE_T | TIME | — |
| FREEZE_BAND | REAL | mg/L |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| MLSS_MG_L | REAL | mg/L |
| OK | BOOL | — |
| INVENTORY_KG | REAL | kg |
| WASTE_INHIBIT | BOOL | — |
| ALM_MLSS_LOW | BOOL | — |
| ALM_MLSS_HIGH | BOOL | — |
| ALM_STALE | BOOL | — |
| ALM_SENSOR_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
MLSS_MON 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
- 7
- Simulated scans
- 374
- 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 MLSS_MON — 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.