LOSS_IN_WEIGHT_FEED
Loss-in-weight continuous feeder with weigh-cycle rate derivation and open-loop volumetric running through refill.
When to use it
Use LOSS_IN_WEIGHT_FEED when a continuous feeder (screw, vibratory or belt) meters an ingredient by mass into a process, its hopper sits on load cells, and the hopper has to be refilled periodically without the controller losing its rate.
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 | — |
| RATE_SP | REAL | kg/h |
| WEIGHT | REAL | kg |
| WEIGHT_OK | BOOL | — |
| CYCLE | TIME | — |
| K_RATE | REAL | (kg/h)/% |
| KP | REAL | % |
| TI_S | REAL | s |
| TRIM_MAX_PCT | REAL | % |
| FEED_MIN_PCT | REAL | % |
| FEED_MAX_PCT | REAL | % |
| REFILL_LO_KG | REAL | kg |
| REFILL_HI_KG | REAL | kg |
| EMPTY_KG | REAL | kg |
| REFILL_SETTLE | TIME | — |
| REFILL_TMO | TIME | — |
| DEV_PCT | REAL | % |
| DEV_DLY | TIME | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| FEED_PCT | REAL | % |
| ACT_RATE | REAL | kg/h |
| VALID | BOOL | — |
| VOLUMETRIC | BOOL | — |
| REFILL_CMD | BOOL | — |
| HOPPER_LOW | BOOL | — |
| TOTAL_KG | REAL | kg |
| ALM_RATE_DEV | BOOL | — |
| ALM_REFILL_TMO | BOOL | — |
| ALM_EMPTY | BOOL | — |
| ALM_WT_GAIN | BOOL | — |
| ALM_WT_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
LOSS_IN_WEIGHT_FEED 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
- 334
- 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 LOSS_IN_WEIGHT_FEED — 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.