FB_BA_ShdObjEntry

The function block FB_BA_ShdObjEntry serves for the administration of all shading elements in a facade, which are globally saved in a list of shading elements. It is intended to facilitate the input of the element information - also with regard to the use of the visualization. A schematic representation of the objects with description of the coordinates is shown in Shading correction: principles and definitions.

The shading elements are declared in the global variables:

VAR_GLOBAL
     arrShdObj : ARRAY[1..BA_Param.nSunPrt.nMaxShdObj] OF ST_BA_ShdObj;
END_VAR

Each individual element aShdObj[1] to aShdObj [nMaxShdObj] carries the information for one shading element (ST_BA_ShdObj). This information consists of the selected type of shading (rectangle or sphere) and the respectively associated coordinates. For a rectangle, these are the corner points (fP1x, fP1y, fP1z), (fP2x, fP2y, fP2z), (fP3x, fP3y, fP3z) and (fP4x, fP4y, fP4z) for a sphere this are the center point (fMx, fMy, fMz) and the radius fRads. In addition, the phase of the shading can be defined via the inputs nBegMth and nEndMth, which is important in the case of objects such as trees that bear no foliage in winter.

The function block thereby directly accesses the field of this information via the IN-OUT variable aShdObj.

Note: The fact that the rectangle coordinates fP2x, fP2z, fP4x, fP4y and fP4z are output values results from the fact that they are formed from the input parameters:

fP2x = fP1x; fP2z = fP1z; fP4x = fP3x; fP4y = fP1y; fP4z = fP3z;

That limits the input of a rectangle to the extent that the lateral edges stand vertically on the floor (fP2x = fP1x and fP4x = fP3x), that the rectangle has no inclination (fP2z = fP1z and fP4z = fP3z) and can only have a different height "upwards", i.e. in the positive y-direction (fP4y = fP1y).

The function block is used in three steps:

• Read
• Change
• Write

Read

Selection of the element from the list aShdObj[nId] is based on the entry at nId. A rising edge on bRd reads the data. These values are assigned to the input and output variables of the function block. These are the input values fP1x, fP1y, fP1z, fP2y, fP3x, fP3y, fP3z, fMx, fMy, fMz, fRads, the object enumerator eType and the output values fP2x, fP2z, fP4x, fP4y and fP4z. It is important here that the input values are not overwritten in the reading step. Hence, all values can initially be displayed in a visualization.

Change

In a next program step the listed input values can then be changed. If a rectangle is preselected at input eType via the value "eObjectTypeTetragon", the output values fP2x, fP2z, fP4x, fP4y, and fP4z result from the rectangle coordinates that were entered (see above).

The values entered are constantly checked for plausibility. The output bErr indicates whether the values are valid (bErr=FALSE). If the value is invalid, a corresponding error message is output at output sErrDescr .
If a rectangle is defined, only the inputs fP1x, fP1y, fP1z, fP2y, fP3x, fP3y and fP3z must be written to, the inputs fMx, fMy, fMz and fRads need not be linked. For a sphere definition, only fMx, fMy, fMz and fRads have to be described; the rectangle coordinates can remain unlinked

Write

The parameterized data are written to the list element with the index niId upon a positive edge on bWrt , regardless of whether they represent valid values or not. The element structure ST_BA_ShdObj therefore contains a plausibility bit bVld, which forwards precisely this information to the function block FB_BA_ShdCorr to prevent miscalculations.

This approach is to be regarded only as a proposal. It is also possible to parameterize the function block quite normally in one step and to write the values entered to the corresponding list element with a rising edge on bWrt.

Inputs

VAR_INPUT
  nId         : UDINT;
  bRd         : BOOL;
  bWrt        : BOOL;
  fP1x        : REAL;
  fP1y        : REAL;
  fP1z        : REAL;
  fP2y        : REAL;
  fP3x        : REAL;
  fP3y        : REAL;
  fP3z        : REAL;
  fMx         : REAL;
  fMy         : REAL;
  fMz         : REAL;
  fRads       : REAL;
  nBegMth     : UDINT;
  nEndMth     : UDINT;
  eType       : E_BA_ShdObjType;
END_VAR

Remark about the shading period:

The month entries must not be 0 and not be greater than 12, all other combinations are possible.
Examples:
Start=1, End=1: shading in January.
Start=1, End=5: shading from the beginning of January to the end of May.
Start=11, End=5: shading from the beginning of November to the end of May (of the following year).

/ Inputs/Outputs

VAR_IN_OUT
  aShdObj: ARRAY[1..BA_Param.nSunPrt_MaxShdObj] OF ST_BA_ShdObj;
END_VAR

Outputs

VAR_OUTPUT
  fP2x       : REAL;
  fP2z       : REAL;
  fP4x       : REAL;
  fP4y       : REAL;
  fP4z       : REAL;
  bErr       : BOOL;
  sErrDescr  : T_MAXSTRING;
END_VAR

Requirements