CLB_VNTR: Venturi valve calibration function

The CLB_VNTR block is used for automatic or manual calibration of an air valve. Calibration data is used to calculate valve position for a requested air flow.

During automatic calibration, the valve actuator is commanded to a series of predefined positions and air volume flow is measured at each position. If the resulting collected data contains enough "pairs" (position - air flow) and the pairs form a monotonically increasing air volume flow curve, the calibration is considered successful. With a successful calibration, valid air flow data is copied from the inactive table into the active table to be used during normal operation.

Result of the calibration is provided at Present value property of the associated MCalcVal object.

Compatible data points:
Multistate calculated value [MCalcVal]

Refer to data point objects for a detailed description of the BACnet data points.

Required properties:

Present value
Tracking value
State flag
Reliability
Enabled subsystem specific extension: Venturi valve

Pin description (inputs)

BaObjRef
BA-Object reference Structure [BaObjRef] defines a bound connection between XFB and BACnet object. The binding occurs automatically. Manual configuration attempts are not necessary and can result in system errors.
DeviceId	Device identifier Double word (default value: 16#3FFFFF) [DeviceId] comprises object type and object instance in a single identifier. It is used to identify device object: local or remote. Local device object could also be identified by value 16#3FFFFF.
ObjectId	Object identifier Double word (default value: 16#3FFFFF) [ObjectId] comprises object type and object instance in a single identifier. It is used to identify object within a device.
ItemId	Item identifier Integer (default value: -1) [ItemId] represents an item index in the functional view node object, which references the BACnet object. [ObjectId] and [ItemId] together define an indirect access reference to the BACnet object. Value -1 indicates that direct binding is used.

ClbCmd
Calibration command Integer (default value: 1) The command to be ran.
= 1	Ready
= 2	Calibrate (starts calibration process: automatic air flow data collection)
= 3	Apply (evaluates data in inactive table and updates calibration status; if inactive table is considered acceptable, active table is set with new values)
= 4	Cancel (cancels calibration process for automatic air flow data collection; calibration status is set to Failed and inactive table is reset)

AirFl
Air volume flow Real (default value: 0.0 m3/h) The current air volume flow as measured by sensor.

AirFl

Air volume flow

Real (default value: 0.0 m3/h)

The current air volume flow as measured by sensor.

AirFlMin
Minimum air volume flow Real (default value: 0.0 m3/h) Air volume flow level below which the signal loses accuracy and flow feedback is no longer useful. (duct velocity 350fpm (1.778 meter/s) is a low limit value that may be used to help determine [AirFlMin])

AirFlMin

Minimum air volume flow

Real (default value: 0.0 m3/h)

Air volume flow level below which the signal loses accuracy and flow feedback is no longer useful. (duct velocity 350fpm (1.778 meter/s) is a low limit value that may be used to help determine [AirFlMin])

TshAflMin
Threshold for minimum air volume flow Real (default value: 0.1 m3/h) The minimum difference between measured air flow and [AirFlMin], below which the system will consider the air flow as being equal to [AirFlMin].

TshAflMin

Threshold for minimum air volume flow

Real (default value: 0.1 m3/h)

The minimum difference between measured air flow and [AirFlMin], below which the system will consider the air flow as being equal to [AirFlMin].

SrchAtp
Search attempts Integer (default value: 5) The number of search attempts for valve position that corresponds to minimum air flow. Minimum: 0 Maximum: 10

SrchAtp

Search attempts

Integer (default value: 5)

The number of search attempts for valve position that corresponds to minimum air flow.

Minimum: 0
Maximum: 10

TiRnActr
Actuator run time Time (default value: 90s) The time for actuator movement from 0% to 100%. Minimum: 0 Maximum: 300s

TiRnActr

Actuator run time

Time (default value: 90s)

The time for actuator movement from 0% to 100%.

Minimum: 0
Maximum: 300s

TiHld
Holding time Time (default value: 3s) The time for air flow settling after valve position change. Minimum value allowed: 0 Maximum value allowed: 300s

TiHld

Holding time

Time (default value: 3s)

The time for air flow settling after valve position change.

Minimum value allowed: 0
Maximum value allowed: 300s

MsngPrd
Measuring period Time (default value: 5s) The time for measuring air flow. Average value for air flow is calculated during the measuring period. Minimum: 0 Maximum: 300s

MsngPrd

Measuring period

Time (default value: 5s)

The time for measuring air flow. Average value for air flow is calculated during the measuring period.

Minimum: 0
Maximum: 300s

AflCtlMod
Control mode for air volume flow Boolean (default value: True) Defines whether closed or open loop is used in valve control.
1 (True)	Closed loop
0 (False)	Open loop

AflCtlMod

Control mode for air volume flow

Boolean (default value: True)

Defines whether closed or open loop is used in valve control.

1 (True)

Closed loop

0 (False)

Open loop

SpAirFl
Setpoint air volume flow Real (default value: 0.0 m3/h) Requested air volume flow. During normal operation, data from active table will be used to calculate the valve position needed for the requested air volume flow.

SpAirFl

Setpoint air volume flow

Real (default value: 0.0 m3/h)

Requested air volume flow. During normal operation, data from active table will be used to calculate the valve position needed for the requested air volume flow.

PrVlvPos
Present valve position Real (default value: 0.0%) Valve position used to calculate value of output pin [AirFlClb]. During normal operation, data from active table will be used to calculate expected air flow when valve is set with present valve position value. Minimum: 0.0% Maximum: 100.0%

PrVlvPos

Present valve position

Real (default value: 0.0%)

Valve position used to calculate value of output pin [AirFlClb]. During normal operation, data from active table will be used to calculate expected air flow when valve is set with present valve position value.

Minimum: 0.0%
Maximum: 100.0%

Pin description (outputs)

PrVal
Present value Integer (default value: 1) The present value of the referenced MCalcVal BACnet object. [PrVal] will deliver the last valid value if [Valid] = False.
1:Initial	Valve has not been calibrated. Block provides 0.0 for calculated valve position value and air volume flow calibration value.
2:Failed Calibration	An attempt for calibration has been made, but the data in the inactive table is not acceptable and will not be set in the active table.
3:Calibrated	Valve has been successfully calibrated (either automatically or manually). The block provides calculated values based on data from active table.

VlvPosVal
Valve position value Real (default value: 0.0%) The calculated valve position based on the active table data and [SpAirFl]. Minimum: 0.0% Maximum: 100.0%

VlvPosVal

Valve position value

Real (default value: 0.0%)

The calculated valve position based on the active table data and [SpAirFl].

Minimum: 0.0%
Maximum: 100.0%

AirFlClb
Air volume flow calibration value Real (default value: 0.0 m3/h) The calculated air volume flow based on the active table data and [PrVlvPos].

AirFlClb

Air volume flow calibration value

Real (default value: 0.0 m3/h)

The calculated air volume flow based on the active table data and [PrVlvPos].

NumClbPts
Number of valid calibration points Integer (default value: 0) The number of valid pairs in the active table. Minimum: 0 Maximum: 16

NumClbPts

Number of valid calibration points

Integer (default value: 0)

The number of valid pairs in the active table.

Minimum: 0
Maximum: 16

TiRmgClb
Remaining calibration time Time (default value: 0s) The estimated time left until the calibration process is expected to be completed. Minimum: 0s Maximum: 900s (15min)

TiRmgClb

Remaining calibration time

Time (default value: 0s)

The estimated time left until the calibration process is expected to be completed.

Minimum: 0s
Maximum: 900s (15min)

Valid
Valid Boolean (default value: False) An indication of whether output pin [PrVal] is reliable.
1 (True)	[PrVal] is reliable. XFB can access the BACnet object. AND Fault flag in state flag property = 0 (no fault) (Reliability = 0 (no error) or Reliability was not detected). AND Subsystem specific extension properties are accessed successfully.
0 (False)	[PrVal] is not reliable. XFB cannot access the BACnet object. OR Fault flag in state flag property = 1 (fault) (Reliability ≠ 0). OR Subsystem specific extension properties are not accessed successfully.

Valid

Boolean (default value: False)

An indication of whether output pin [PrVal] is reliable.

1 (True)

[PrVal] is reliable.

XFB can access the BACnet object.

AND

Fault flag in state flag property = 0 (no fault)
(Reliability = 0 (no error) or Reliability was not detected).
AND
Subsystem specific extension properties are accessed successfully.

0 (False)

[PrVal] is not reliable.

XFB cannot access the BACnet object.

Fault flag in state flag property = 1 (fault)
(Reliability ≠ 0).
OR
Subsystem specific extension properties are not accessed successfully.

ErrClb
Calibration error Integer (default value: 1) Provides additional information for the valve in case of error.
1	No Error
2	Operation: Valid pairs in active table less than 2 or higher than maximum
3	Operation: Not monotonically increasing active table
4	Calibration: First measurement is below minimum air flow
5	Calibration: Incorrect configuration
6	Calibration: Write error - inactive table
7	Calibration: Write error - state [failed calibration]
8	Apply: Not enough valid pairs in inactive table
9	Apply: Read error - inactive table
10	Apply: Write error - active table and state
11	Apply: Write error - state [not enough valid pairs]
12	Apply: Write error - state [read inactive table error]
13	Cancel: Cancel command ran
14	Cancel: Write error - inactive table and state
15	Startup: Not monotonically increasing active table
16	Startup: Not enough valid pairs in the active table
17	Startup: Read error - active and inactive table
18	Startup: Write error - state
19	Status update : Read error
20	Properties update: Write error
21	General: Incorrect reference

ErrCode
Error code indication Integer (default value: 20) The status of the last performance of the XFB read operation.
= 0	No error.
> 0	Error, see XFB error codes.

ErrCode

Error code indication

Integer (default value: 20)

The status of the last performance of the XFB read operation.

= 0

No error.

> 0

Error, see XFB error codes.

RErrNr
Error number while reading Integer (default value: 16383) Provides additional error information for read operation.

RErrNr

Error number while reading

Integer (default value: 16383)

Provides additional error information for read operation.

ErrWrit
Error while writing Integer (default value: 20) The status of the last performance of the XFB write operation.
= 0	No error.
> 0	Error, see XFB error codes.

ErrWrit

Error while writing

Integer (default value: 20)

The status of the last performance of the XFB write operation.

= 0

No error.

> 0

Error, see XFB error codes.

WErrNr
Error number while writing Integer (default value: 16383) Provides additional information for write operation.

WErrNr

Error number while writing

Integer (default value: 16383)

Provides additional information for write operation.