> For the complete documentation index, see [llms.txt](https://support.powerio.com/hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.powerio.com/hub/codesys-hvac/en/hvac-modbus-library/functionblocks/belimo/belimo_vru_d3_bac_easy.md). # BELIMO\_VRU\_D3\_BAC\_EASY ## `BELIMO_VRU_D3_BAC_EASY` (FB) `FUNCTION_BLOCK` BELIMO\_VRU\_D3\_BAC\_EASY ### Representation
InOut: | Scope | Name | Type | Initial | Comment | | ----------- | ----------------------- | ----------------------------------- | ------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | Input | `xEn` | `BOOL` | TRUE | Enable / disable communication (TRUE = enable) | | Input | `byUnitId` | `BYTE` | 0 | Device address | | Input | `xUpdateActual` | `BOOL` | FALSE |

Update of actual values (on every rising edge
)

| | Input | `xUpdateSetp` | `BOOL` | FALSE |

Update of setpoints (on every rising edge
)

| | Input | `xResError` | `BOOL` | FALSE |

Reinitialization of the outputs eErrorCodeCom or
stErrorCodeDev to the fault-free state (on every rising edge)

| | Input | `rSetpPerc` | `REAL` | 0.0 | Setpoint in % (0.0 - 100.0 %) depending on application | | Input | `eOverrideCon` | BELIMO\_VRU\_D3\_BAC\_OVERRIDE\_CON | BELIMO\_VRU\_D3\_BAC\_OVERRIDE\_CON.NO\_OVERRIDE |

Airflow control: setpoint - airflow in % (0.0 - 100.0 %) (0.0 % = Vmin, 100.0 % = Vmax)
Forced override of the air damper (0 = none)

| | Inout | `ModbusClient` | `ModbusClientBase` | | Client of the device | | Output | `rVminM3H` | `REAL` | | Minimum value - airflow in m3/h | | Output | `rVmaxM3H` | `REAL` | | Maximum value - airflow in m3/h | | Output | `rVnomM3H` | `REAL` | | Nominal airflow in m3/h | | Output | `rVolFlowM3H` | `REAL` | | Actual value of the airflow in m3/h | | Output | `rSetpPercFb` | `REAL` | | Feedback of the setpoint in % (0.0 - 100.0 %) | | Output | `eCommandFb` | BELIMO\_VRU\_D3\_BAC\_COMMAND | | Feedback of the triggering of test functions (0 = none) | | Output | `eOverrideConFb` | BELIMO\_VRU\_D3\_BAC\_OVERRIDE\_CON | |

Feedback of the forced override of the air damper (0 =
none)

| | Output | `xAlarm` | `BOOL` | FALSE | Collective fault (TRUE = fault) | | Output | `xAlarmCom` | `BOOL` | FALSE | Collective fault - communication (TRUE = fault) | | Output | `eErrorCodeCom` | ModbusErrorCode | | Error code - communication (0 = no error) | | Output | `stErrorCodeDev` | `STRING` | | String with the numbers of the active device errors | | Output | `xBusy` | `BOOL` | | Communication indicator (TRUE = communication) | | Input Const | `eCommand` | BELIMO\_VRU\_D3\_BAC\_COMMAND | BELIMO\_VRU\_D3\_BAC\_COMMAND.NO\_COMMAND | Triggering of test functions (0 = none) | | Input Const | `xSetpVolumeFlowMinMax` | `BOOL` | FALSE |

Triggering the transfer of the parameters rSetpVolumeFlowMin
or rSetpVolumeFlowMax (on every rising edge)

| | Input Const | `rSetpVolumeFlowMax` | `REAL` | 2000.0 |

Setpoint for the maximum volume flow in the selected
volume flow unit (at rSetpVolFlowPerc = 100.0 %)

| | Input Const | `rSetpVolumeFlowMin` | `REAL` | 500.0 |

Setpoint for the minimum volume flow in the selected
volume flow unit (at rSetpVolFlowPerc = 0.0 %)

| | Input Const | `tBusFailureTimeOut` | `TIME` | TIME#10s0ms |

Duration for activation of the state
Communication error (t = 0s = disabled, for t >= 10s
(at least 10 s) the parameter must rSetpVolFlowPerc
must be transferred cyclically with a time interval < t)

| | Input Const | `rBusFailurePos` | `REAL` | 100.0 |

Position of the damper in the event of a bus failure (in %, 100% =
open)

| | Input Const | `tTimeUpdateSetp` | `TIME` | TIME#45s0ms |

Update interval for the processes influenced by the input
xUpdateSetp influenced

| | Input Const | `tTimeUpdateActual` | `TIME` | TIME#3s0ms |

Update interval for the processes influenced by the input
xUpdateActual influenced

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