CRAC_DX_CTRL
DX CRAC compressor staging on return-air temperature with anti-cycle protection and a supply-air low limit.
When to use it
Use CRAC_DX_CTRL when a direct-expansion computer-room air conditioner cools on return-air temperature with one or more compressor stages, and the compressors must be protected from short-cycling and the coil from being driven to its low limit.
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 | — |
| RAT_PV | REAL | degC |
| RAT_OK | BOOL | — |
| SAT_PV | REAL | degC |
| SAT_OK | BOOL | — |
| RAT_SP | REAL | degC |
| STAGES | USINT | — |
| UP_DB | REAL | K |
| DN_DB | REAL | K |
| STAGE_DLY | TIME | — |
| SAT_LO_LIMIT | REAL | degC |
| SAT_LO_DLY | TIME | — |
| FAIL_STAGES | USINT | — |
| HI_DEV | REAL | K |
| HI_TMO | TIME | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| STAGE_ON | USINT | — |
| SAT | REAL | degC |
| AT_CAPACITY | BOOL | — |
| ALM_T_FAULT | BOOL | — |
| ALM_SAT_LOW | BOOL | — |
| ALM_HIGH_RAT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 9
- Simulated scans
- 492
- 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 CRAC_DX_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.