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Representation Model Configuration 

DDS 

Data 

Declaration 

System 

Franz Lohberger 

Jun-05 

Page: 1





Content 

Overview and Concept 

Mapping Scheme and Representation Model 

Configure mappingScheme and mappingElements 

The MappingScheme Wizard 

Objectives: 

After completing this unit you will: 

• know the concept of mappingSchemes 

• be able to choose the correct schemes for your model(s) 


Jun-05 

Page: 2





Overview 

• What is a representation model? Why is a representation 

model needed? 

DDS mappingScheme 

C-code 

model 

ASAP2 

Record-Layout 

• The DDS model must cover both the C-code model and 

the ASAP2 model 


Jun-05 

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How does a map look like in the C-Code? 

(A) with ‚global‘ axis 

header file 

extern const int myMap[6]; 

source file 

const int myMap[6] = {1,2,3,4,5,6}; 

(B) with ‚global‘ axis and axisSize field 

header file 

extern const int myMap[1+6]; 

source file 

const int myMap[1+6] = 

{6, 

1,2,3,4,5,6}; 

(C) with ‚local‘ axis (map is an array, values are 

alternating) 

header file 

extern const int myMap[6][2]; 

source file 

const int myMap[6][2] = { 

{256,1}, 

{512,2}, 

{768,3}, 

{1024,4}, 

{1280,5}, 

{1536,6}}; 

(D) with ‚local‘ axis (map is an array) 

header file 

extern const int myMap[1+6+6]; 

source file 

const int myMap[1+6+6] = 

{6, 

256,512,768,1024,1280,1536, 

1,2,3,4,5,6}; 

(E) with ‚local‘ axis (map is a structure) 

header file 

extern const struct myMap_STRUCT { 

int xSize; 

int xDist[6]; 

int values[6]; 

} myMap; 

source file 

const struct myMap_STRUCT myMap = 

{6, 

{256,512,768,1024,1280,1536}, 

{1,2,3,4,5,6}}; 

etc. 


Jun-05 

Page: 4





Mapping Scheme & Representation Model 

Mapping Scheme for 

Parameters 


Axis 


Maps 


Online Values 


cBase definitions 


Jun-05 

Page: 5





Mapping Scheme 

Special c-Code mapping for the datatype 

of the definition, e.g. 

always export the ‚builtin‘ dataType (even 

if there is a typedef ‚chain‘ in DDS) 

Important flags which influence the appearance of 

the data in the C-Code and/or in the ASAP2 file: 

The attributes isValBlk, isAscii and isLibbit are only 

allowed for arrays of online, parameter, and cBase. 

These trigger another handling of the init values for 

these arrays. 

The attribute isAlternate makes only sense for 

map's with an embedded axis and means that the 

values for the axis and for the map alternate. 

The attribute byRows makes only sense for map's 

with at least two axis and means that the values 

corresponding the axis are exchanged. For a map 

with two axis with size 3 and 5 the map values are a 

map of size [5,3] not [3,5]. 

The attribute isEmbedded makes only sense for 

axes. Axes with a mapping scheme that has that 

attribute set are contained in the memory of their 

corresponding map and are embedded. 

There are two classes of memory layout's. The 

whole data structure is a C struct with members for 

the different parts of the memory layout or the 

whole data structure is an array and the members 

occupy different parts of this array. In the second 

case the attribute isArray is set to true. 


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Mapping Elements - Principle 

• A mapping scheme contains several (but at least one) mapping 

elements. 

• Usually, a mapping element corresponds to one ‚index‘-attribute of 

the ASAP2 RECORD_LAYOUT 

• The most important attribute of the mappingElement is the ‚kind‘ 

attribute which controls the mapping to ASAP2: 

value of ‚kind‘ attribute of 

mappingElement 

values 

axisSize 

axisValues 

reserved 

... 

corresponding attribute of 

RECORD_LAYOUT 

FNC_VALUES 

NO_AXIS_PTS_‘x‘ 

AXIS_PTS_‘x‘ 

RESERVED 

... 


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Mapping Elements 

Most important attribute: 

Says what's the contents of the 

mappingElement: The values of 

the map or the axis, the size of 

the second axis or some 

unknown value 

Determines for what axis 

(1, 2, or 3) this axis 

specific element in the 

map will be used. 

axisNumber = -1 means: 

this element represents all 

axis. 

Special c-Code mapping 

for the datatype of the 

definition 

Name of the C struct 

member for this element. 

Only allowed for axis values 

and says that the axis values 

must be decreasing, normally 

they are increasing 

Select a 


Only allowed for axis values and means that the axis values have room 

for fixAxisSize values regardless of the size of the axis. (The axis is only 

allowed to be smaller then fixAxisSize). 

Add a new 

mappingElemen 

t 

Modify current 


DataType for this 

mappingElement. If the 

dataType is missing the 

elemType of the entity using this 

mappingScheme will be used 

Says that the value is not stored 

in this element but a pointer of 

the given size is stored in this 

element. 

Only allowed for map values 

and says that the array 

representing the map values 

has not size [2,3,4] for axis with 

length 2, 3, and 4 but size 

[2*3*4]. 

Change order of 

mappingElements 


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Example 

Example: 

In DDS, there is the map ‚myMap‘ which 

- has the mappingScheme ‚myScheme‘ (see below) assigned 

- has the dataType ‚int‘ and the init-values ‚1‘, ‚2‘, ‚3‘, ‚4‘ 

- has the embedded axis ‚someAxis‘ with the dataType ‚int‘ and the axisSize ‚4‘ assigned 

C-Code 

/* declaration (*.h) */ 

extern struct myMap_STRUCT { 

int x; 

int y; 

} myMap[4]; 

/* definition (*.c) */ 

struct myMap_STRUCT myMap[4] = 

{ 

{256, 1}, 

{512, 2}, 

{768, 3}, 

{1024, 4}}; 

Axis 

values 

Map 

values 

DDS mappingScheme 

mappingSchemeMap ‚myScheme‘ { 

displayName = { „my Scheme"; } 

alternate = true; 

mappingElements = ( 

mappingElement { 

kind = axisValues; 

axisNumber = 1; 

memberName = "x"; 

} 

mappingElement { 

kind = values; 

memberName = "y"; 

} 

) 

} 

ASAP2 Record_Layout 

/begin RECORD_LAYOUT myScheme 

AXIS_PTS_X 1 SWORD INDEX_INCR 

DIRECT 

FNC_VALUES 2 SWORD 

ALTERNATE_WITH_X DIRECT 

/end RECORD_LAYOUT 


Jun-05 

Page: 9





The MappingScheme Wizard (1) 

The MappingScheme Wizard 

• gives an overview about the used DDS mapping schemes 

• gives the possibility to change the assigned mapping schemes in a consistent and 

convenient way 

The MappingScheme Wizard can be launched: 

• Automatically by the ASAP2 Import (in 'CodeMode‘) 

• By using the MappingScheme Wizard entry in the Project menu or the icon in the 

main toolbar (contains all entities) 

• Via the context menu (contains only entities within the current scope) 

Start the MappingScheme Wizard on 

the current database 


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The MappingScheme Wizard (2) 

List of available 

mapping schemes 

Step 1: select a 

mapping scheme 

Step 2: select those 

entities (of the current mapping 

scheme) which should be assigned 

to another compatible mapping 

scheme 

Step 3: Drag and Drop 

the selected entities to 

a compatible mapping 

scheme 


Jun-05 

Page: 11





Summary 

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Jun-05 

Page: 12

DDS - Visu

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