Distributed Engineering Data Management (EDM) using HyperText

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1 Distributed Engineering Data Management (EDM) using HyperText Nils Høimyr CERN/CN Computer Support for Engineering (CE) group Juha Lappalainen CERN/PPE, Institute of Particle Physics Technology, Helsinki The CMS Collaboration Lars-Johan Rehn CERN/AT The Atlas Collaboration October 12, 1993 ABSTRACT This paper describes an Engineering Data Management (EDM) system for the LHC Detector Design projects. The aim of distributed EDM is to integrate collaborative institutes and companies connected to Internet and to provide them with tools for exchanging information between remotely located design teams.

2 Contents 1. Introduction Principle HyperText documents for EDM... 4 Example Users Recommended data types... 9 HTML... 9 ASCII... 9 Postscript... 9 IGES... 9 Other Graphics formats Recommended tools Hypertext browser Line-mode browser...10 FTP archive WWW server Platform requirements User commitment necessary...11 References Contents i

3 1. Introduction The large number of institutes and design teams involved in the projects for the LHC experiments need efficient exchange of information and technical data. Due to the fact that different Institutes and departments have their own way of organizing engineering data, an information sharing system which allows management of distributed data in a heterogeneous environment is required. The data management system should be robust enough to cover the whole life-time of an experiment. This paper describes an Engineering Data Management (EDM) system for the LHC Detector Design projects. The aim of distributed EDM is to integrate collaborative institutes and companies connected to Internet and to provide them with tools for exchanging information between the remotely located design teams. The system is based on publicly available (i.e. no license costs involved) software products and networking facilities. This makes the EDM system easy to accept and join, which is a key factor for succesful implementation. The feasiblity of such a system is proved by pilot projects implemented within the ATLAS [1] and CMS [2] collaborations. Introduction 1

4 2. Principle An information retrieval system based on hypertext 1 through the World Wide Web (WWW) [3] is used to assist distributed design activities. The World Wide Web is a global hypertext system originating at CERN which can handle text and graphics information. The overall data management task is divided into managing separate design projects, which each take care of presenting the status of their own work. This is done by using explanatory WWW HyperText documents with links to design files and to information server directories (see FTP -archive in chapter 6.) containing more dynamic design data. EDM Design Data Released Draft v. 1.3 Draft v. 1.2 Project 1 Project 2 Other information Project 1 Sub-projec t Design Data FTP Sub-project Design Data FTP Other Internet Network Logical view in WWW Physical system structure Figure 1. The distibuted engineering information mapped into one logical entity under WWW. The EDM system itself is based on a "metadata" concept. It basically means that the management of the actual engineering data is based on data about the actual data, the "metadata". Metadata might be e.g. short descriptions of drawings, release dates, names, owners or computeroriented information like file sizes, types, creation dates etc. 1 HyperText is a concept where text documents are linked to each other thus forming a presentation that can be followed in the order of reader's choice. Principle 2

5 The EDM system described is built using metadata in HyperText documents. The HyperText documents are linked together to form a framework for the management of the data. The HyperText documents can be edited and linked freely to conform to each data management need. In addition to fixed HyperText documents we use the so called "directory browsing"; a feature of the browsers to present a dynamic view to an FTP archive containing engineering data. This gives an access to non-released, frequently changed design data. Since the actual engineering data is kept in standard formats and the EDM system is actually a layer of HyperText documents on top of the data, future changes are simplified. The data can be quite easily remapped, e.g onto an industrial PIM (Product Information Management) system. Principle 3

6 3. HyperText documents for EDM The HyperText pages guide users to the information they are looking for. Each project will have a default "Home Page" which contains short textual descriptions and links to sub-projects. The projects and sub-projects use : Links to a HyperText or Graphics gallery of released (and therefore stable) drawings. This can be organized as a common database containing (links to) the project's official design data and updated by authorized EDM adminstrators only. These documents present released drawings in either text only or with embedded graphics. Text only presentation can be followed with any browser. The graphics gallery is meant to be browsed with NCSA XMosaic, or another browser which handles embedded.gif images. A link to text documentation (.html files in a "docs" directory). HyperText documents for EDM 4

A directory browsing link to design data on an FTP server. This can be more dynamic design data, typically CAD exchange files during the product development phase.

7 A directory browsing link to design data on an FTP server. This can be more dynamic design data, typically CAD exchange files during the product development phase. Or a dynamic archive for a distributed design team on a common design task. Figure 2: A link to an FTP archive containing PostScript printouts of various design versions and releases (the browser is NCSA's Xmosaic). Links to contact persons and their coordinates. HyperText documents for EDM 5

8 Example An example of how to structure design data for easy access through WWW is available for the Silicon Tracker for LHC design. The following document can be found in an URL address: Figure 3: Silicon Tracker project's EDM. HyperText documents for EDM 6

9 The graphical gallery of released drawings is a convenient format for presentation purposes. It is especially directed for new viewers learning about the designs, but can as well be used to archive of released (and thus stable) design versions. Figure 4: A graphical gallery of released drawings. HyperText documents for EDM 7

10 4. Users The users of the EDM system can be grouped into three categories with different objectives: Anyone interested to browse the EDM pages or anyone interested to use the FTP archive. In this case the user has only read access and can take a copy of all of the visible documents. EDM users within a project. The system manager can give persons in a project user-id's with read/write permissions in their FTP area so that they can maintain their own FTP directories. The administrators, who have full permission to the whole EDM system, have the principal responsibility to update the HyperText EDM documents. These persons can also be a project member assigned to look after EDM information. Users 8

11 5. Recommended data types Previewing of data is limited by the capabilities of the browsers, but any file format can be transferred using FTP. Currently access to native CAD-data bases will require human intervention, but the hypertext can contain information about how to obtain the original data. The data in the HyperText system can have following formats: HTML The HyperText EDM documents are text in HTML format. This format can be used to present any textual information, given that there is a conversion from a native file format to HTML. Small documents can be converted manually (or drafted in HTML in the first place). ASCII Ascii text can be imbedded in it's original format in an HTML document. Postscript Design data should as a default be put on the FTP server in Postscript (.ps) format for remote previewing. IGES CAD models should be available in a neutral format like IGES or SET, which can be retrieved and read into other CAD-systems. (ISO STEP 1 should be used in the future) Other Graphics formats XMosaic can browse several bitmap formats. GIF files are most common since that is also the format of the imbedded images in an HTML document. 1 STandard for the Exhange of Product data. Recommended data types 9

12 6. Recommended tools Hypertext browser The hypertext browser is the user interface to the system. Through the browser one can browse and read documents on the network. Advanced browsers handle also graphics by activating previewers to consult graphics files. Several browsers exists in the Public Domain. We recommend the use of NCSA MOSAIC [4] in an X-window environment, as this is a powerful WWW browser with many other useful functions. With XMosaic, previewing of remote PostScript files (and several other formats) is possible. Extensions with previewing of CAD-files by starting up the CADapplication directly (for example AutoCAD by the file extension.dwg) from XMosaic can be envisaged. Currently there is also a beta version of Mosaic for Macintosh with similar features with Xmosaic. Line-mode browser All systems should also have the WWW linemode browser installed to give access also for terminal users. This is the most basic way to access the EDM system and is available virtually for any piece of networked computer equipment.a WWW Telnet server is another program that gives access for anybody over telnet, not having a user-id for the server 1. FTP archive FTP (File Transfer Protocol) provides a simple way to exchange files between platforms. The FTP archives should be used as exchange areas 2 for CAD design files in neutral formats like IGES. (CAD files native to a given system can also be exchanged this way) An anonymous FTP server can be setup with public access for general design data, or with group access to some directories for specific projects. WWW server The Engineering information hypertext pages need to reside on a WWW server. Such a server can be set up on any workstation with free disk space, since it does not require much CPU time. Still, if possible, a separate server is recommended for easier maintenance, better availability and system security. 1 These are available by anonymous FTP from info.cern.ch. 2 E.g. the FTP server of Computer Aided Detector Design (CADD) group at CERN. The server's address is cadd.cern.ch. Recommended tools 10

13 7. Platform requirements Network access to Internet. X-windows on Unix operating system (or VMS) to run XMosaic. An X- terminal, PC (XVision) or a Macintosh (MacX) can be also be used connected to a server that has XMosaic installed. Also GhostView 1 and XV 2 (both Public Domain) are needed to preview PostScript and other images. A beta version of a native Mosaic for MAC is also available. It looks and functions like Xmosaic and thus seems promising. One can start using it, but we recommend to upgrade to an official release when it is available. (Mosaic for Microsoft PC Windows will also be available soon from NCSA). The WWW Linemode browser runs on most platforms and can be accessed from any terminal. 8. User commitment necessary How well the system will work in the long run depends on the users' commitment to use it properly. Each project needs some responsible person for updating information pages on the Web. This maintenance should not require more than say, 1 man-hour pr. week, but is essential for successful use of the system. With dedication from the users it is clear that this system provides an efficient tool for exchanging information in the LHC collaborations and will certainly speed up the engineering work in the project. For more information, please contact the authors. 1 This is available by anonymous FTP from prep.ai.mit.edu in /pub/gnu or ftp.cs.wisc.edu in /pub/ghost. 2 This is available by anonymous FTP from export.x.org or export.lcs.mit.edu in /contrib. Platform requirements 11

14 References [1] F. Dynak, P. Jenni, et al., "Atlas: Letter of Intent for a General Purpose pp Experiment at the Large Hadron Collider at CERN", CERN, CH-1211 Geneva 23, Switzerland, 1st Oct [2] M. Della Negra et al., "Letter of Intent by the CMS Collaboration for a General Purpose Detector at the LHC", CERN, CH-1211 Geneva 23, Switzerland, 1st Oct [3] Tim Berners-Lee et al., "World Wide Web book", CERN/ECP, available in hypertext, PostScript and ascii by anonymous FTP at info.cern.ch. [4] Marc Andreessen, "NCSA Mosaic Technical Summary", Software Development Group, National Center for Supercomputing Applications, 605 E. Springfield, Champaign IL 61820, available in PostScript by anonymous FTP at ftp.ncsa.uiuc.edu in /Web/mosaic-papers. [5] P.M.Ferran et al., "minutes from Computer Aided Design (CADD) meetings", available from Mik Ferran, CERN/CN, CH-1211 Geneva 23, Switzerland. [6] Ulf Hordvik, Roland Oehlmann, "Support of Collaborative Engineering through a Shared High Level Product Model", available by anonymous FTP at cadd.cern.ch in /doc. [7] Juha Lappalainen, "Data Networking in building of an Experiment for LHC", Institute of Particle Physics Technology, CH-1211 Geneva 23, Switzerland. References 12

Darren S. Foltinek, Robert R. Stewart, and Don C. Lawton

Electronic documents and the World Wide Web Darren S. Foltinek, Robert R. Stewart, and Don C. Lawton ABSTRACT This paper provides an overview of document information structure, describes the World Wide