> 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/trox/trox_vru_budn.md). # TROX\_VRU\_BUDN ## `TROX_VRU_BUDN` (FB) `FUNCTION_BLOCK` TROX\_VRU\_BUDN ### Representation
InOut: | Scope | Name | Type | Initial | Comment | | ----------- | ----------------------- | --------------------------------- | -------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Input | `xEn` | `BOOL` | TRUE | Enable / disable communication (TRUE = enable) | | Input | `byUnitId` | `BYTE` | 0 | Address of the device | | 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 (at each
rising edge)

| | Input | `rSetpVolFlowPerc` | `REAL` | 0.0 |

Setpoint - volumetric flow in % (0.0 - 100.0 %) (0.0 % =
Vmin, 100.0 % = Vmax)

| | Input | `xEnDevice` | `BOOL` | FALSE |

Enable / disable of the volumetric flow controller (FALSE =
forced control CLOSED, TRUE = no forced control)

| | Inout | `ModbusClient` | `ModbusClientBase` | | Client of the device | | Output | `rVminUnit` | `REAL` | |

Minimum value - volumetric flow in the selected
volumetric flow unit

| | Output | `rVmaxUnit` | `REAL` | |

Maximum value - volumetric flow in the selected
volumetric flow unit

| | Output | `rVnomUnit` | `REAL` | | Nominal volumetric flow in the selected volumetric flow unit | | Output | `rDamperPosPerc` | `REAL` | |

Absolute position of the damper in percent (0.0% =
Closed, 100.0% = Open)

| | Output | `rDamperPosDegree` | `REAL` | | Absolute position of the damper in degrees | | Output | `rVolFlowPerc` | `REAL` | | Actual value of the volumetric flow in percent of the nominal volumetric flow | | Output | `rVolFlowM3H` | `REAL` | | Actual value of the volume flow in m3/h | | Output | `rVolFlowUnit` | `REAL` | |

Actual value of the volumetric flow in the selected
volumetric flow unit

| | Output | `rSetpVolFlowPercFb` | `REAL` | |

Feedback of the setpoint - volumetric flow in % (0.0 - 100.0 %
) (0.0 % = Vmin, 100.0 % = Vmax)

| | Output | `eCommandFb` | TROX\_VRU\_BUDN\_COMMAND | | Feedback of the triggering of test functions (0 = none) | | Output | `eOverrideConFb` | TROX\_VRU\_BUDN\_OVERRIDE\_CON | |

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

| | Output | `eActuatorType` | TROX\_VRU\_BUDN\_ACTUATOR\_TYPE | | Type of the actuator | | Output | `eVolumeFlowUnitFb` | TROX\_VRU\_BUDN\_VOLUMEFLOW\_UNIT | |

Feedback of the unit for the specification of the absolute
volumetric flows (1 = m3/h)

| | Output | `eSetpSourceFb` | TROX\_VRU\_BUDN\_SETP\_SOURCE | |

Feedback of the source for the setpoint (0 = Analog, 1 =
Bus)

| | Output | `eBusTermin` | TROX\_VRU\_BUDN\_BUS\_TERMINATION | | State of the Modbus termination resistor (1 = active) | | Output | `eSensorTypeFb` | TROX\_VRU\_BUDN\_SENSOR\_TYPE | |

Feedback of the type of the connected sensor (0 = none
)

| | Output | `sSerialNum` | `STRING` | | Device serial number | | Output | `wFirmwareVer` | `WORD` | | Firmware version of the device | | Output | `rSensorValue` | `REAL` | | Current actual value of the sensor | | Output | `xSensorOffsetInDevice` | `BOOL` | |

Indication whether the sensors must be calibrated in the device
(TRUE = calibration in the device required, FALSE = calibration in
the FB required)

| | Output | `rSetpAnalog` | `REAL` | | Setpoint in XXX.X % (0.0 - 100.0 %) based on the sensor | | 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 | `rSensorValueOffset` | `REAL` | 0.0 |

Constant measurement offset for the transmitted voltage -
actual value

| | Input Const | `eSensorType` | TROX\_VRU\_BUDN\_SENSOR\_TYPE | TROX\_VRU\_BUDN\_SENSOR\_TYPE.NO\_SENSOR |

Influence: Outputs: rSensorValue
Type of the connected sensor (0 = none)

| | Input Const | `eSetpSource` | TROX\_VRU\_BUDN\_SETP\_SOURCE | TROX\_VRU\_BUDN\_SETP\_SOURCE.BUS | Source for the setpoint (0 = Analog, 1 = Bus) | | Input Const | `eCommand` | TROX\_VRU\_BUDN\_COMMAND | TROX\_VRU\_BUDN\_COMMAND.NO\_COMMAND | Triggering of test functions (0 = none) | | Input Const | `eVolumeFlowUnit` | TROX\_VRU\_BUDN\_VOLUMEFLOW\_UNIT | TROX\_VRU\_BUDN\_VOLUMEFLOW\_UNIT.M3\_PER\_H |

Unit for the specification of the absolute volumetric flows (1 =
m3/h)

| | Input Const | `xSetpVolumeFlowMinMax` | `BOOL` | FALSE |

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

| | Input Const | `rSetpVolumeFlowMax` | `REAL` | 180.0 |

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

| | Input Const | `rSetpVolumeFlowMin` | `REAL` | 0.0 |

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

| | Input Const | `rPositionTimeOut` | `REAL` | 0.0 |

Setpoint of the position in the event of an active communication fault
(0.0 - 100.0%, 0.0% = Closed)

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

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

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

Update interval for the operations that are influenced by the input
xUpdateSetp influenced

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

Update interval for the operations that are influenced by the input
xUpdateActual influenced

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