3D PLM PPR Hub Open Gateway

External PDM System

This section succinctly defines what is a PDM and what is its role either in the CATIA V5 integration, or intrinsically.

Definition

A product data management (PDM) system is a software that enables manufacturers to store, archive, manage and control engineering information, specifically, data surrounding new product designs and engineering processes.

The data is:

• Files: CATIA V5 document files and their associated files.
• Meta data: document attributes and document relationship information.

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Integration with CATIA V5

The purpose of the integration between an external PDM System and CATIA V5 is to enable the management of the data from CATIA V5 within the PDM. It consists in implementing a communication channel between them through which the data are transferred under the PDM control. 

Fig.1 Integration Functional View

The data which are stored into the PDM are always created in a CATIA V5 session. These data, V5 documents, must be saved on disk to be persistent. It is this persistent view which will be stored in the PDM. Once the documents are in the PDM it can be encrypted into a secure vault, but in all cases the PDM must give back the same V5 documents as those provided by CATIA V5.

The scenario consisting in transfering CATIA V5 documents to the external PDM system is named Check-In scenario. In opposite, the scenario consisting in extracting CATIA V5 documents from the external PDM system is named Check-Out scenario. They are main scenarios that you should implement for this integration.

The Client Integration is the CATIA software used by the integration scenario to:

• Control the consistency of the persistent documents
• Make easier the file transfer  to the PDM
• Provide information to fill up the PDM meta data.

The purpose of the external PDM system is to manage V5 documents in its file repository. However, CATIA, and only CATIA, ensures the V5 document consistency by this software layer. This software layer is the APIs of the CATxPDMInterfaces framework, and which requires the PX1 license.

The user Work area is the dedicated directory to store the persistent files accessible by CATIA. This directory is the exchange area for files transfer between the two applications.

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Document Management Capability

The document into the external PDM system can be seen as a set of information that we can sum up like this:

• Key Attributes
• Meta Data
• Revision Status ( Release, In work )
• Edition Status (Lock or unlock)
• Representation 1 (the V5 document file)
• Representation 2 (the Preview file of the V5 document)

The PDM system should propose a Document Management capability. It means provide services to be able to do:

• Document Registration: Initialize a reference to a document into the PDM
• Document Identification by key attributes
• Document Check-In:  Store a document into the PDM vault
• Document Check-Out: Extract a document from the PDM vault
• Document Encryption: Secure the document  
• Document Revision status Management: Release, In work
• Document Edition Status Management: Lock or unlock a document (check out a document locks a document, but it can be another reasons)

The Check-In and Check-Out scenarios use these base services.

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CATIA V5 Concepts

This section presents the main concepts of the CATIA V5 in the domain of the documents.

V5 Document Links

As you perform design operations within a CATIA session, CATIA creates internal links between documents. In the following example [Fig.2], the publication "Face" belonging to Part1 has been copied and pasted "as result with link" in Part2 in the Product1 context.

Fig.2 Copy and Paste in Assembly Context

Within the interactive session, the end user can use the Links command (in the Edit menu) to understand the type of links, in other words their semantic. This information can only be visible into an interactive session, since only CATIA application can provide the link's information. The Fig.3 is the snapshot of the Links command describing the links semantic from Product1.

Fig.3 Edit/Links Command For Product1

The Fig.4 is the snapshot describing the links semantic from Part2.

Fig.4 Edit/Links Command For Part2

The following picture, Fig.5, is a schematic view of these links with their semantic.

Fig.5

You can also use the Desk command (in the File menu) to display the network of documents in session [Fig.6].

Fig.6

The graph is organized in such way that root documents appear on the left [Fig.6]. A root document is the document associated with the object which manages the visualization of this document, and its components. This object is an editor. Refer to the Wintop Frame articles for more details about the editor.

The document are interactively made persistent on disk using the Save Management command. But once the document are outside a CATIA Session, an external PDM system does not have access to the relationship between the documents, and consequently does not have access also to the type of links between document.

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Consistent Set of Documents

The Consistent Set Of Documents is a group of documents. These documents may have dependencies (links) on other documents. The group becomes a Consistent Set of Documents when all theses dependencies are solved within the group. This means that the whole CATIA design intent is captured in this group of documents, and, then by modifying, moving, renaming theses documents in this special context ensures that the knowledge is kept consistent and secure.

The Integration scenarios should never process a document as single document but should always consider this document in the context of the Consistent Set of Document this document belongs to.

The identification of a Consistent Set of Document must be performed among the persistent files saved on disk. The integration must ensure that the V5 documents still in session are saved in the user Work area before computing the Consistent Set.

We recommend the following methodology to identify the consistent set

1. First, identify the root documents contained in the user Work area. A root document is a document being at the top of the dependency hierarchy 
2. For a root document, compute the document dependencies and check that there is no missing document that would break the consistency of the group 
3. Among the several Consistent Set of documents you have retrieved from the Root documents, locate in which Set your document belongs to

Applying this methodology, you are able to identify to which set every document of the user Work area belongs to. Refer to the "Checking the Consistent Set of Files for V5 Documents" [6] use case for details about the consistent set of documents and the root documents.

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Document Properties

A CATIA V5 document contains properties:

• Standard properties
  • CN_PART_NUMBE
  • CN_REVISON
  • CN_DEFINITION
  • CN_NOMENCLATURE
  • CN_DESCRIPTIONREF
  • CN_SOURCE
  • CN_VOLUME
  • CN_MASS
  • CN_SURFACE
• User properties

Interactively you modify or create new user properties using the Properties command ( Contextual menu) , or using the Fx command [Fig.7].

Fig.7 Command to Create & Modify Document Properties

The CATIxPDMItem interface enables you to retrieve or modify the document properties.

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Integration Specifications

This section first presents four identified scenarios to implement. Then it points the main rules to be followed to ensure a successful integration.

Scenario Cases

In the first section, two scenarios have been identified [Fig.1]

• Check-In Scenario [1]

  Check-In is a scenario whereby CATIA session information and persistent documents are used to create new or modify existing PDM system data. Check-In enables save a consistent set of documents from CATIA V5 in the external PDM system with the appropriate document links exposure. These document links information must be sufficient for the Integration to compute the right consistent set of documents once the documents are stored in the PDM, and not anymore under CATIA control.

• Check-Out Scenario [2]

  Check-Out is a scenario whereby CATIA V5 documents are extracted from the PDM system repository to be opened in the interactive CATIA session. Check-Out enables extract a consistent set of documents that has been checked-In previously. It reuses the document link information, stored at Check-In step, to compute the consistent set of documents in order to ensure the CATIA session consistency.

Beside these two base scenarios, two others can be implemented:

• Rename scenario [3]

  Rename is a scenario whereby a document already stored in PDM system is renamed. The consistent set of document this document belongs to must be updated accordingly in order to keep links integrity.

• Derivative Design Copy Scenario [4]

  Derivative Design Copy is a scenario whereby a consistent set of documents stored in a PDM system is duplicated to allow manage a derivative design variant of this set.

These four scenarios, detailed step by step in dedicated articles, referenced by the number in brackets, can be implemented by an interactive or a batch command. For interactive commands, it can be recommended to insert these commands in an Add-in of the General workshop. It enables the end user to benefit these commands whatever the active document type. Refer to the frame article [5] to have complete information about this specific Add-in.

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Rules to be Followed

The integration implementation must enforce the following rules:

1. Work with consistent set of documents

   Even you want to rename, to store, or to display one document, you must work with the consistent set of documents belonging to the selected document. It is the only one way to ensure the document links consistency.  

   In the same way, you should never save one document, but always a consistent set of documents. Interactively, the end user should invoke the Save management command, and by code you have the SaveSessionToDirectory method of the CATxPDMSessionServices class.

2. Let the Product Structure operations under the CATIA V5
control

You must not modify the structure of a Product document outside an CATIA V5 Session, otherwise you are sure to lost the document links consistency. It is valid for any kind of V5 document type. CATIA V5 controls, and then guarantees the data consistency.

3. Use the User Work area [Fig.1]

   It is a dedicated directory to transfer the V5 documents between the two applications.

   • The PDM system extracts document from its secure repository, and copies them into the dedicated directory
   • The Save operation driven by a CATIA session is done in this same directory

   You must be sure that this directory

   • Cannot be shared by several users ( one directory for one user)
   • Is under CATIA control 
   • Is not used for any purpose than Save management, Check-In and Check-Out operations.

   It is mandatory that the documents, once copied into the user Work area, have their original CATIA document names. Moreover, if the document is loaded in session it must not be removed from the user Work directory.

4. Ensure CATIA V5 Document identification within the PDM

   Every CATIA document name must be unique inside the PDM system.

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In Short

The integration consists mainly in implementing two scenarios:

• Check-In
• Check-Out

These scenarios, such as all integration scenarios must never process one document, but the consistent set of documents  this document belong to. It is the only mean to ensure the document links consistency. By using the specific CATIA V5 software layer (PX1 APIs - CATxPDMInterfaces framework) in your scenarios, it guarantees that the exchange between the two applications will be safely done.

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References

History

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