DCV_CTRL
Demand-controlled ventilation — differential-CO2 outdoor-air reset between the base minimum and the design maximum, rate-limited and failing to MAXIMUM.
When to use it
Use DCV_CTRL when a zone or air-handling unit varies its outdoor-air rate with occupancy inferred from CO2, between a base building ventilation minimum and a design-occupancy maximum, per the ASHRAE 62.1 ventilation-rate procedure.
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 | — |
| ZONE_CO2 | REAL | ppm |
| CO2_OK | BOOL | — |
| CO2_SP | REAL | ppm |
| OA_CO2 | REAL | ppm |
| PROP_BAND | REAL | ppm |
| MIN_OA | REAL | l/s |
| MAX_OA | REAL | l/s |
| MIN_OA_UNOCC | REAL | l/s |
| RAMP_RATE | REAL | l/s per s |
| HI_ALM_PPM | REAL | ppm |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| OA_FLOW_SP | REAL | l/s |
| DEMAND_PCT | REAL | % |
| VALID | BOOL | — |
| ALM_CO2_HIGH | BOOL | — |
| ALM_CO2_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 11
- Simulated scans
- 151
- 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 DCV_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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