SCREEN_CTRL
Bar-screen rake control on differential level and a backstop timer, with jam retry, lockout and blinding alarm.
When to use it
Use SCREEN_CTRL when a mechanically raked bar screen or band screen protects an inlet works or a pumping station, the rake is started from the differential level across the screen, and a jammed rake must retry a limited number of times before it is taken out of service.
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 | — |
| DIFF_LEVEL | REAL | mm |
| DL_OK | BOOL | — |
| DL_START | REAL | mm |
| DL_STOP | REAL | mm |
| DL_HIGH | REAL | mm |
| RUN_T | TIME | — |
| CYCLE_T | TIME | — |
| REST_T | TIME | — |
| BLIND_T | TIME | — |
| MAX_RETRY | USINT | — |
| JAM | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| RAKE_RUN | BOOL | — |
| DEMAND | BOOL | — |
| TIMED_MODE | BOOL | — |
| BLIND_PCT | REAL | % |
| PASSES | UDINT | — |
| RETRIES | USINT | — |
| RAKE_H | REAL | h |
| ALM_JAM | BOOL | — |
| ALM_BLINDED | BOOL | — |
| ALM_DL_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
SCREEN_CTRL 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
- 186
- 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 SCREEN_CTRL — 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.