[CenFcd21] Central facade function for automatic

Program block, name / node subtype: [CenFcd21] Central facade function for automatic

Library hierarchy: Coordination

Family: CenFcd

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Diagram

Configurator

info

Program blocks are stored in the library without I/Os. Use the auto-create and auto-connect functions to create I/Os and/or to connect them to the interface blocks, e.g., R_A, CMD_B. Alternatively, take the I/Os from the folder containing the predefined I/Os in the library and/or from the plant and connect them to the interface blocks.

Function

CenFcd21 manages central information used for automatic functions in a facade segment and distributes it either to subordinate application functions (AF) CenFcdShd11 or directly to the connected rooms.

A facade segment has windows with the same:

  • azimuth and slope
  • shading product
  • sun, e.g., shadows from above
  • shadows from the horizon and neighboring buildings
    This is relevant if you do not use the option "Anti-glare protection calculation with interface for annual shading calculation".
Mandatory elements

Name

Description

Type

Alarm / Notification class

Trend / Type

PrGrpCmdSbElm

Present group command for subordinate elements

MCalcVal: Multistate calculated value

N/A

Yes, 4

SolAzRel

Relative solar azimuth angle

ACalcVal: Analog calculated value

N/A

N/A

SolEtRel

Relative solar elevation angle

ACalcVal: Analog calculated value

N/A

N/A

SolRdDir

Direct solar radiation on facade

ACalcVal: Analog calculated value

N/A

N/A

Lngit

East longitude

ACnfVal: Analog configuration value

N/A

N/A

Latit

North latitude

ACnfVal: Analog configuration value

N/A

N/A

FcdIncl

Facade angle of inclination

ACnfVal: Analog configuration value

N/A

N/A

FcdAzmth

Facade azimuth angle

ACnfVal: Analog configuration value

N/A

N/A

CenFcdShdMngr

Manager central facade for shading

GrpMaster: Group manager

N/A

N/A

Solar angle

The solar angle on the facade (Relative solar azimuth angle, Relative solar elevation angle) is calculated from the geographic location, facade orientation, and date and time. It determines whether the sun is shining on the facade sector.

The following values are provided as BACnet objects for monitoring:

  • Relative solar azimuth angle (SolAzRel)
  • Relative solar elevation angle (SolEtRel)
  • Direct solar radiation on facade (SolRdDir)

Optionally, information from the annual shading computer can be used to account for shadows from buildings and the horizon.

More settings (Parameters in the chart "Configuration (Central facade function for automatic)")

Parameter

Description

Default value

BlsTypCnf

Configuration blinds type

1: Blinds, position number
2: Blinds, angle
3: Blinds, height and angle
4: Awnings, height

1: Blinds, position number

SolAglLeft

Solar position angle range left

-90...90 [°]

85 [°]

SolAglRight

Solar position angle range right

-90...90 [°]

85 [°]

SolAglUp

Solar position angle range up

-90...90 [°]

85 [°]

SolAglDwn

Solar position angle range down

-90...90 [°]

85 [°]

SlatPosHrz

Slat position horizontal

Theoretical slat percentage to horizontally position slats.

-200...200 [%]

Blinds height is the total mechanical range of the blinds.
0 % = High
100 % = Low

20 [%]

SlatPosVrt

Slat position vertical

Theoretical slat percentage to vertically position slats.

-200...200 [%]

Slat angle in % is the total mechanical range for a blinds height of 100%.
0 % = Open
100 % = Closed
The parameters are used to internally calculate % to angle degrees for the comparison with the solar position.
Example slats are horizontal at 0 %, but can only be closed to 60°.
SlatPosHrz = 0 %
SlatPosVrt = 150 %

100 [%]

HgtSolPosHi

Height for high solar position

0...100 [%]

40 [%]

HgtSolPosLo

Height for low solar position

0...100 [%]

60 [%]

SolEtOpn

Solar elevation for opening

Height 0 %

-90...90 [°]

60 [°]

DlyOffSolDirHi

Switch-off delay for direct solar radiation by high solar position

0...3600 [s]

1200 [s]

DlyOffSolDirLo

Switch-off delay for direct solar radiation by low solar position

0...3600 [s]

60 [s]

Limits to direct solar radiation

The following factors limit radiation through windows:

  • The wall thickness (angle range left and right). You can configure this using SolAglLeft and SolAglRight.
  • The wall thickness above balconies. You can configure this with SolAglUp.
  • The horizon. You can configure this with SolAglDwn.

Delay after direct solar radiation

Glare does not stop immediately when the sun stops shining on the facade. Glare depends on solar elevation and on local conditions, e.g., reflections, bright surfaces, rounded edges.

You can define a switch-off delay in the function, where the function calculates the value based on time and facade orientation:

  • DlyOffSolDirHi (at vertical solar radiation)
  • DlyOffSolDirLo (at horizontal solar radiation)

Blinds type (strategy)

You can configure the blinds type and its response.

Strategy

Description

1

Blinds, position number (P-position)

Control blinds with 4 different slat positions (P-positions). It defines a slat angle in the lowered position (height 100 %).

Positions must be predefined in the actuator. They do not need to be specifically set. This strategy is suitable for almost all standard blinds.

2

Blinds, angle

The strategy is used only if the actuator does not support position numbers. Control is by height (always 100 %) and the corresponding slat angle.

3

Blinds, height, and angle

Blinds are adjusted based on sunlight in height as well as slat angle. The strategy is suitable for special applications, e.g., for blinds that move from bottom to top.

This requires detailed planning at the object.

4

Awnings, height (shadow edge)

The awning height is controlled based on solar position, so that the shadow edge is always at the same location in the room.

This requires detailed planning at the object.

Strategy 1: P-position

Projected solar angle

Slats angle

P-position

0°...10°

60°

P1: Visual protection

10°...25°

45°

P2: Anti-glare, sun position low

25°...40°

25°

P3: Anti-glare, sun position high

40°...90°

0°

P4: Open

Strategy 2 and 3: Slats angle as function of project solar elevation

Strategy 3 and 4: Height position as a function of relative solar elevation

These values are examples. You can configure them as follows for the individual room layout. On-site measurements serve as the basis.

Solar elevation

Height

0...30 [°]

100 [%] (closed)

30...50 [°]

HgtSolPosLo (default 60 %)

50...SolEtOpn [°] (default 60°)

HgtSolPosHi (default 40 %)

SolEtOpn...90 [°] (default 60°)

0 [%] (open)

The function calculates a new value up to a maximum of 8 times per day. This provides solid anti-glare without disturbing the user with frequent actuator movements.

Further options

Description

Group command for sub-elements delay 1

Elements that belong to this option:

Central operating mode delay 1 | ICnfVal: Integer configuration value

Manager central facade shading delay 1 | GrpMaster: Group manager

Group command for sub-elements delay 2

Elements that belong to this option:

Central operating mode delay 2 | ICnfVal: Integer configuration value

Manager central facade shading delay 2 | GrpMaster: Group manager

Group command for sub-elements delay 3

Elements that belong to this option:

Central operating mode delay 3 | ICnfVal: Integer configuration value

Manager central facade shading delay 3 | GrpMaster: Group manager

Central manual operation

Elements that belong to this option:

Central manual operation | MCnfVal: Multistate configuration value

Central manual operation (Blinds height) | ACnfVal: Analog configuration value

Central manual operation (Slat angle) | ACnfVal: Analog configuration value

Central manual operation (Blinds position number) | MCnfVal: Multistate configuration value

Central anti-glare protection

Elements that belong to this option:

Effective brightness | ACalcVal: Analog calculated value

Brightness switch-on limit | ACnfVal: Analog configuration value

Brightness switch-off limit | ACnfVal: Analog configuration value

Indirect brightness switch-on limit | ACnfVal: Analog configuration value

Indirect brightness switch-off limit | ACnfVal: Analog configuration value

Darkness switch-on limit | ACnfVal: Analog configuration value

Darkness switch-off limit | ACnfVal: Analog configuration value

Central thermal protection

Elements that belong to this option:

Effective solar radiation | ACalcVal: Analog calculated value

Solar radiation at high condition | ACnfVal: Analog configuration value

Solar radiation at medium condition | ACnfVal: Analog configuration value

Solar radiation at low condition | ACnfVal: Analog configuration value

More details about the option "Central anti-glare protection"

Further options

Description

Central manual operation for anti-glare protection condition

Elements that belong to this option:

Central manual operation (Anti-glare protection condition) | MCnfVal: Multistate configuration value

Anti-glare protection calculation

Anti-glare protection calculation with interface for annual shading calculation

Elements that belong to this option:

Indirect anti-glare protection angle | ACnfVal: Analog configuration value

Central brightness from weather station

Central brightness from facade

Additional criterion based on solar radiation and outside temperature

info

Use either "Anti-glare protection calculation" or "Anti-glare protection calculation with interface for annual shading calculation"
Use either "Central brightness from weather station" or "Central brightness from facade".

Parameters in "Anti-glare protection calculation"

Name

Default value

Enable indirect angle

0

Indirect angle

90°

Maximum light sensitivity delay (at ADA_DLY)

1 h

Minimum light sensitivity delay (at ADA_DLY)

15 min

Switch-on delay brightness

1 min

Parameters in "Anti-glare protection calculation with interface for annual shading calculation"

Name

Default value

Maximum light sensitivity delay (at ADA_DLY)

1 h

Minimum light sensitivity delay (at ADA_DLY)

15 min

Switch-on delay brightness

1 min

Parameters in "Central brightness from weather station"

Name

Default value

Angle correction

0°

Minimum sensors count for calculation

3

Switch-on delay brightness

Reduction factor

More details about the option "Central thermal protection"

Optional elements

Name

Description

Type

Alarm / Notification class

Trend / Type

CenManOpSolCnd

Central manual operation for solar radiation condition

MCnfVal: Multistate configuration value

N/A

N/A

Further options

Description

Central solar radiation from weather station

Solar radiation from facade

info

Use either "Central solar radiation from weather station" or "Solar radiation from facade".

Parameters in "Central thermal protection"

Name

Default value

Solar radiation switch-on delay

20 min

Solar radiation switch-off delay

20 min

Further information

Delayed operation

There are three more group managers for delayed operation. The goal is to distribute the rooms to more group managers and make sure that not all rooms change their operating mode at the same time.

CenFcd21 is part of the building scope and can be used in two ways:

  • For commanding of subordinate central functions in the floor scope
  • For commanding of subordinate room controllers in the room scope

The following diagram provides an overview of the two ways.

It is unlikely to have both options in parallel. There are two possible topologies:

Cascading of the central functions is necessary.

Cascading of the central functions is not necessary.