List of unsupported and restricted elements

This article contains information about the possible usage of logi.CAD 3 elements as described in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Reference documentation") when logi.CAD 3 is used to develop safety-relevant applications . Those logi.CAD 3 elements might be:

  • a feature (see logi.CAD 3 user documentation, "→Feature"),

  • a →data type as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Supported data types (in ST)"),

  • a functionality of a feature or

  • a system block or a system data type of the system libraries Standard, System or Arduino as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "System blocks for the application")

Warning 1

Observe the following:

  1. Only use elements that are described in the reference documentation of logi.CAD 3. Do not use any undocumented elements.

  2. When a documented feature is listed as unsupported in this article, do not use any functionality of this feature when developing safety-relevant applications.

  3. When the documented functionality of a feature is listed as unsupported in this article, do not use this functionality when developing safety-relevant applications.
    When other functionalities of the same feature are not listed as unsupported in this article, these other functionalities are allowed to be used.

  4. When a documented system block or a documented system data type is listed as unsupported in this article, do not use this block or data type when developing safety-relevant applications.

Therefore, the following is valid: When an element is documented and not listed in this article, its usage when developing safety-relevant applications is allowed.

Warning 2

It is imperative to consider the warnings included within the logi.CAD 3 user documentation (see logi.CAD 3 user documentation, "User documentation of the development environment"), when using the supported elements for developing safety-relevant applications. Above all but not only observe the warnings about recursions, invalid connections, and conflicts.
In particular, the descriptions of the system blocks must be examined and considered accordingly (see logi.CAD 3 user documentation, "System blocks for the application").

Moreover when using any supported system block that is providing an internal error diagnostic, it is imperative that the application ensures that error conditions do not lead to any loss of the safety function. This is possible as follows:

  • either by processing the output ENO of the supported system block

  • or by ensuring that the described default output behavior does not affect the safety function

See the logi.CAD 3 user documentation, "Execution control: EN, ENO" for details on the output ENO and for a list of blocks providing an internal error diagnostic. Observe that this list contains all system blocks of logi.CAD 3 – hence, the unsupported system blocks are also included in this list.
See the reference documentation of the system block, sub-section "Internal error diagnostic for block" for details when an error is detected while executing this block with internal error diagnostic.

Contents of this article:

Unsupported features

The following features of logi.CAD 3 are not supported. Subsequently, do not use any functionality of this feature (as described/listed in the appropriate section describing this feature).

Moreover, the following of the →debugging/testing/→tracing features as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Testing, debugging and tracing the application") are not qualified to be used for verification/validation of the safety-relevant application.

Warning 3

However, you are able to use those features and their functionalities (as described/listed in the appropriate section describing the feature) as supporting measures for bug analysis purposes. For instance, the Values of Variables view can be used as a supporting measure to display selected →variables and monitor their values on the safety system in logi.CAD 3.

Warning 4

From the available debugging/testing/tracing features, only the test framework feature is supported as a test tool (see logi.CAD 3 user documentation, "Testing single POUs by using the test framework").

Restricted usage of C-blocks

Function blocks implemented in →C (so-called "C-blocks") must be used on the condition that they are only used in →libraries. This condition applies to the following descriptions of the logi.CAD 3 reference documentation:

Unsupported data types

The following data types as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Supported data types (in ST)") are not supported:

  • STRING

  • CHAR

The following data types as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Supported data types (in ST)") are only supported, if the system integrator has integrated them for developing safety-relevant applications:

  • REAL

  • LREAL

Subsequently, contact the system integrator for information on whether the data types REAL and LREAL are supported or not supported.

Warning 5

If the data types REAL and LREAL are indeed supported, observe that the result of system blocks processing these data types REAL and LREAL is integration-dependent and may therefore differ between different integrations – in particular, if the result of the system block is located within the threshold of REAL and LREAL data types. Subsequently, contact the system integrator for the appropriate threshold information.

Unsupported/restricted functionalities of ST

The following functionalities for the →ST -editor as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Creating application in ST-editor") are not supported:

Observe that the following pragmas as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Declaration of internal variables in ST") are not supported (the declaration of internal variables is supported, as long as supported elements are used) :

  • { instanceParam }

  • { noCodeGeneration }

  • { @RELATES_TO := ...;}

Observe that the following functionalities of the ST-editor might change other →POUs besides the currently edited POU:

In case of any doubts about which POUs will be changed, do not use these functionalities.

Unsupported/restricted functionalities of FBD

The following functionalities for the →FBD-editor as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Creating application in FBD-editor") are not supported:

Observe that the following functionalities of the FBD-editor might change other POUs besides the currently edited POU:

In case of any doubts about which POUs will be changed, do not use these functionalities.

Unsupported system blocks and system data types

The system blocks and system data types are specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "System blocks for the application" and "System data types for the application" respectively) .
images/s/b2ic8e/9012/1ca6q62/_/images/icons/emoticons/information.svg The unsupported system blocks are grouped into types "string blocks", "enhanced blocks" etc. to make this section more comprehensive.

String blocks

String blocks require logi.CAD 3 string support runtime and/or functions from the file string.h . These blocks have one or more parameters of data type STRING .

The following string blocks are not supported:

Enhanced blocks

Enhanced blocks are enhancements to the blocks defined in the standard IEC 61131-3. These blocks are included in a sublibrary with the suffix Enh , for instance in the sublibrary BitstableEnh .

The following of the enhanced blocks are not supported:

Enhanced 2D array blocks

Enhanced 2D array blocks are enhanced blocks for bulk operations on variable-sized 2D arrays.

The following enhanced 2D array blocks are not supported:

Enhanced control blocks

Enhanced control blocks are enhanced blocks providing controller functionality.

The following enhanced control blocks are not supported:

Enhanced memory blocks

Enhanced memory blocks are enhanced blocks for memory manipulation.

The following enhanced memory blocks are not supported:

Enhanced util blocks

Enhanced util blocks are enhanced blocks for testing, debugging and logging purposes.

The following enhanced util blocks are not supported:

Blocks providing platform or runtime-system specific functionality

These blocks are included in the system libraries System or Arduino .

The following blocks providing platform or runtime-system specific functionality are not supported:

Blocks for mathematical operations

Such blocks require mathematical functions defined in the file math.h .

The following blocks for mathematical operations are only supported, if the system integrator has integrated a math library that is qualified for developing safety-related applications:

Subsequently, contact the system integrator for information on whether these blocks for mathematical operations are supported or not supported.

Standard convert blocks

Such blocks convert a data type into another data type. They are included in the sublibrary Convert .

If the input of the following standard convert block is connected with REAL or LREAL, this connection variant for the standard convert block is only supported, if the system integrator has integrated a math library that is qualified for developing safety-related applications. The other connection variants are supported independently of the fact of whether a qualified math library is available or not.
Example: The connection variant LREAL_TO_INT for the standard convert block TO_INT is only supported, if a qualified math library has been integrated by the system integrator. The connection variant WORD_TO_INT for the convert block TO_INT is supported regardless.

The standard convert blocks with the possible connection of REAL/LREAL that requires a qualified math library are :

Subsequently, contact the system integrator for information on whether these standard convert blocks are supported or not supported.

ANY_REAL blocks

Such blocks have one or more parameters of data type REAL . and/or LREAL .

The following blocks ANY_REAL blocks are only supported, if the system integrator has integrated the data types REAL . and LREAL . for developing safety-relevant applications:

S ubsequently, contact the system integrator for information on whether the data types REAL and LREAL as well as the ANY_REAL blocks are supported or not supported.

System data types

In logi.CAD 3 , these system data types are usually used in blocks providing platform or runtime-system specific functionality.

The following system data types are not supported:

Unsupported/restricted functionalities when creating custom libraries with user blocks

The following functionalities when creating custom libraries with user blocks (see logi.CAD 3 user documentation, "Creating custom library with user blocks") are not supported:

Observe that the creation of a logi.SAFE library or logi.WEB library is not supported. Hence, the following functionalities/descriptions in the context of a logi.SAFE/logi.WEB libraries are also not supported:

Warning 6

From the available library types as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Declaration of information on creation and references for the library"), only LIBRARYTYPE := LOGICAD; is supported.

Moveover, observe that the following statements/values as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Declaration of information on creation and references for the library" and "Declaration of the contents of the library" respectively) are not supported:

  • statement USES -- its purpose: referencing a library (see also in the above list of unsupported functionalities)

  • values INTERFACE and OBJECT for keyword DEPLOY
    As a consequence, only the value SOURCE is supported for DEPLOY.

  • value PRIVATE for keyword VISIBILITY
    As a consequence, only the value PUBLIC is supported for VISIBILITY.

  • section INCLUDES ... END_INCLUDES

  • section BINARY_OBJECTS ... END_BINARY_OBJECTS

  • section SOURCES ... END_SOURCES

In addition, observe the following, when creating/using a custom library with user blocks for developing safety-relevant applications:

Warning 7

Before a custom library is installed in a project to be used for developing safety-relevant applications, this custom library must be released – in particular, by a qualified person.
images/s/b2ic8e/9012/1ca6q62/_/images/icons/emoticons/information.svg The release process is an organizational measure that needs to be done by qualified persons as specified under the article "Requirements for use".

Warning 8

If a custom library should not be used any longer, delete this custom library from the library provider (see logi.CAD 3 user documentation, "Library provider and library cache") and clean the library cache as described in the reference documentation (see logi.CAD 3 user documentation, "Cleaning the library cache") so that obsolete libraries cannot be installed from the library cache by mistake.

Unsupported functionalities for PLC-specifications

The following functionalities for →PLC-specifications (see logi.CAD 3 user documentation, "PLC-specifications within editor for PLC-object") are not supported:

Warning 9

As more resources are not supported within a configuration, only one resource within a configuration is supported when developing safety-relevant applications.

Moveover, observe that the following statements as specified in the logi.CAD 3 reference documentation (see logi.CAD 3 user documentation, "Declaring more tasks within PLC-object") are not supported:

  • { IO }

  • { IO := IO-service1, IO-service2, ...}