AHU_CTRL
Air-handling unit — sequenced heating / economiser / cooling on supply-air temperature, duct-static fan loop and mixed-air coil protection.
When to use it
Use AHU_CTRL when a built-up or packaged air-handling unit holds a supply-air temperature with a heating coil, an outdoor-air damper and a cooling coil, and a variable-speed supply fan holds a duct static pressure.
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 | — |
| OCC | BOOL | — |
| SA_TEMP_SP | REAL | °C |
| SA_TEMP | REAL | °C |
| SA_OK | BOOL | — |
| MA_TEMP | REAL | °C |
| MA_OK | BOOL | — |
| OA_TEMP | REAL | °C |
| OA_OK | BOOL | — |
| DUCT_SP | REAL | Pa |
| DUCT_PV | REAL | Pa |
| DUCT_OK | BOOL | — |
| SF_PROVEN | BOOL | — |
| MIN_OA_PCT | REAL | % |
| ECON_HI_LIM | REAL | °C |
| ECON_DB_K | REAL | K |
| MA_LOW_LIM | REAL | °C |
| MA_FREEZE | REAL | °C |
| MA_FREEZE_DLY | TIME | — |
| MA_RLS_RATE | REAL | %/s |
| KP_T | REAL | %/K |
| TI_T | TIME | — |
| KP_P | REAL | %/Pa |
| TI_P | TIME | — |
| SF_MIN_PCT | REAL | % |
| SF_FALLBACK_PCT | REAL | % |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| SF_SPEED | REAL | % |
| CLG_VLV | REAL | % |
| HTG_VLV | REAL | % |
| OA_DMPR | REAL | % |
| ECON | BOOL | — |
| SEQ_PCT | REAL | % |
| VALID | BOOL | — |
| ALM_MA_LOW | BOOL | — |
| ALM_MA_WARN | BOOL | — |
| ALM_SA_FAULT | BOOL | — |
| ALM_MA_FAULT | BOOL | — |
| ALM_DUCT_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 14
- Simulated scans
- 571
- 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 AHU_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.