IEEE Std C37.232-2007 IEEE Recommended Practice for Naming Time Sequence Data Files.pdf

IEEE Std C37.232-2007 IEEE Recommended Practice for Naming Time Sequence Data Files IEEE 3 Park Avenue New York, NY 10016-5997, USA 22 August 2007 IEEE Power Engineering Society Sponsored by the Power System Relaying Committee C37.232 TM IEEE Std C37.232-2007 IEEE Recommended Practice for Naming Time Sequence Data Files Sponsor Power System Relaying Committee of the IEEE Power Engineering Society Approved 22 March 2007 IEEE-SA Standards Board Abstract: A procedure for naming time sequence data (TSD) files, such as files produced by digital fault recorders, power swing recorders, power quality monitors, and so on is recommended. The sources of TSD files are described, and a survey of current naming techniques is provided. The advantages of using a common naming procedure are highlighted, and the limitations and applications are identified. Issues of compatibility across operating systems and various vintages, and adaptability to other types of files are also discussed. The required and optional portions of the naming procedure are described in detail, and many examples are provided. Keywords: comma separated values, CSV, company name, device identifier, fault data, fault time, file extension, filename, file name, file naming convention, required fields, start date, start time, station identifier, time code, time sequence data, TSD, user fields The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York, NY 10016-5997, USA Copyright © 2007 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 22 August 2007. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Introduction This introduction is not part of IEEE Std C37.232-2007, IEEE Recommended Practice for Naming Time Sequence Data Files. Microprocessor-based measurement and protection devices (digital devices) used in electric power substations produce large quantities of time sequence data (TSD) files that contain vast volumes of data about the power system. Additional TSD files are also produced while processing the original data and while performing maintenance and testing operations on the original devices. Many problems are associated with handling such large quantities of TSD files. The term “handling” means reporting, saving, archiving, exchanging, and so on. The problems are mainly due to the fact that currently there are too many different types of proprietary naming conventions in circulation. Work on this project began with the IEEE-PES-PSRC Communications Subcommittee task force HTF8 in 1999. Working group H8 then followed, and their report was posted in 2001. Their reported naming convention solved many problems that are associated with handling the large quantities of TSD files. Their main objective was to define a common naming convention. In 2002 a new task force was formed to study the potential of developing the common naming convention into an IEEE Recommended Practice. In 2003 this working group, also designated H8, was formed with the objective of writing this recommended practice. The recommended TSD filename is human readable and includes, among other features, key portions of the information contained in the file, including, but not limited to, the name of the circuit, substation and recording device, and the date and time of initial occurrence. This was not easy to do under older operating systems, which limited file names to 11 characters, but now filenames of up to 253 characters are generally permitted. Notice to users Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:/ standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. Interpretations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this recommended practice may require use of subject matter covered by patent rights. By publication of this recommended practice, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE shall not be responsible for identifying patents or patent applications for which a license may be required to implement an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. iv Copyright © 2007 IEEE. All rights reserved. v Copyright © 2007 IEEE. All rights reserved. Participants At the time this recommended practice was submitted to the IEEE-SA Standards Board for approval, the H8 File Naming Convention Working Group had the following membership: Amir Z. Makki, Chair J. Rick Cornelison, Vice Chair Mark Adamiak John Chadwick Ratan Das Anthony Eshpeter Tony Giuliante Erich Gunther Jim Hackett James W. Ingleson Robert Johnson Mladen Kezunovic Kenneth E. Martin Pierre Martin Harish Mehta Krish Narendra Robert M. Orndorff Jeffrey M. Pond Maria Rothweiler George Semati Larry E. Smith John Sperr Bill Strang Mark Taylor Don Wardlow The following members of the individual balloting committee voted on this recommended practice. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman Steven C. Alexanderson Ali Al Awazi Hugh Barrass William D. Bartholomew David C. Beach Kenneth A. Birt Thomas H. Blair Christoph Brunner Danila Chernetsov Keith Chow Tommy P. Coope J. Rick Cornelison Ratan Das Gary R. Engmann Kenneth J. Fodero Michael J. Garland Jeffrey G. Gilbert Randall C. Groves Roger A. Hedding Steven Hodder Jerry W. Hohn Dennis K. Holstein James W. Ingleson Anders L. Johnson Piotr Karocki J. L. Koepfinger Jim Kulchisky Federico Lopez G. L. Luri Bruce D. Mackie Amir Z. Makki Kenneth E. Martin Gary L. Michel Brian P. Mugalian Jerry R. Murphy Bruce A. Muschlitz Michael S. Newman Robert M. Orndorff Lorraine K. Padden Donald M. Parker Jeffrey M. Pond Peter J. Raschio R. E. Ray Michael A. Roberts Robert A. Robinson Charles W. Rogers Maria Rothweiler M. S. Sachdev Bartien Sayogo Tony L. Seegers Shahriar Semati Mark S. Simon Jerry W. Smith Joshua B. Smith Larry E. Smith Devendra K. Soni Charles R. Sufana Mark Taylor Richard P. Taylor Mark A. Tillinghast Thomas E. Wiedman Oren Yuen When the IEEE-SA Standards Board approved this recommended practice on 22 March 2007, it had the following membership: Steve M. Mills, Chair Robert M. Grow, Vice Chair Don Wright, Past Chair Judith Gorman, Secretary Richard DeBlasio Alex Gelman William R. Goldbach Arnold M. Greenspan Joanna N. Guenin Julian Forster* Kenneth S. Hanus William B. Hopf Richard H. Hulett Hermann Koch Joseph L. Koepfinger* John Kulick David J. Law Glenn Parsons Ronald C. Petersen Tom A. Prevost Narayanan Ramachandran Greg Ratta Robby Robson Anne-Marie Sahazizian Virginia C. Sulzberger Malcolm V. Thaden Richard L. Townsend Howard L. Wolfman *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Alan H. Cookson, NIST Representative Lorraine Patsco IEEE Standards Program Manager, Document Development Matthew J. Ceglia IEEE Standards Program Manager, Technical Program Development vi Copyright © 2007 IEEE. All rights reserved. Contents 1. Overview 1 1.1 Scope. 1 1.2 Purpose 2 1.3 Need for this recommended practice. 2 2. Definitions 2 3. Filenames 2 3.1 General 2 3.2 Naming conventions for TSD files 3 3.3 Coding schemes. 3 4. Recommended file naming convention 4 4.1 General 4 4.2 Limitations. 4 4.3 The required fields. 5 4.4 The user fields . 6 4.5 The extension field 7 4.6 Examples of the file naming convention . 7 4.7 Geographic position (latitude and longitude) 7 4.8 Additional examples 8 4.9 Short filenames 8 5. Uniqueness. 9 6. Universality 9 7. Applications 10 Annex A (informative) Example coding algorithm 11 Annex B (informative) Example source code. 12 Annex C (informative) Bibliography 15 vii Copyright © 2007 IEEE. All rights reserved. 1 Copyright © 2007 IEEE. All rights reserved. IEEE Recommended Practice for Naming Time Sequence Data Files 1. Overview Filenames are essential for both operating systems and users. The filename is the systems key for unlocking the contents, and without friendly names (where key information about the file is in the filename), the user will have trouble handling large numbers of files. Also, programs for analysis and trending applications have to automatically sift through and process large numbers of files. Reading file contents requires considerable disk access time especially for large files. But reading filenames is much faster because the filenames are stored separately from their contents in system files called allocation tables, and these tables can be quickly loaded with minimal disk access time. Meaningful filenames provide software developers with the ability to write programs that can quickly manage and process large numbers of files. The hardware benefits as well from the reduced number of disk access operations. The alternative to meaningful filenames is to build and maintain a specialized database. However, specialized databases are very costly to create and maintain and they use extremely large memory structures. Accordingly, the recommended filename information is specified in comma-delimited format where commas are used to separate the information into multiple fields. Thus, spreadsheet-like tables can be made from directory listings of filenames. Such tables provide users with an easy way to perform sort and query operations based on any one of the fields in the filename, in effect providing the same look and feel as any other specialized database application. 1.1 Scope This recommended practice defines a procedure for naming time sequence data (TSD) files that originate from digital protection and measurement devices, such as transient data records, event sequences, and periodic data logs. The filename includes, among other features, key portions of the information contained in the file, including, but not limited to, the names of the circuit, substation and recording device, and the date and time of event occurrence. IEEE Std C37.232-2007 IEEE Recommended Practice for Naming Time Sequence Data Files 1.2 1.3 2. 3. 3.1 Purpose The purpose of this recommended practice is to define a procedure for naming TSD files, a procedure that is needed to resolve many problems that are associated with reporting, saving, exchanging, archiving, and retrieving large numbers of files. There is no other defined standard for naming such files at this time. Need for this recommended practice The recommended naming convention has been gaining popularity and has so far been used by a nontrivial number of utilities, independent system operators, manufactures, electric reliability commissions, and third- party developers. The North American Electric Reliability Council (NERC) and the Northeast Power Coordinating Council (NPCC) have recommended the use of a common file naming convention. Definitions For the purposes of this document, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standards B51 should be referenced for terms not defined in this clause. 2.1 disallowed character set: The following characters are not allowed in filenames on most operating systems: ? “ / * | : ; $ % (i.e., question mark, quotation mark, forward slash, backward slash, less than, greater than, asterisk, pipe, colon, semi-colon, brackets, dollar sign, percent, and braces). 2.2 filename character set: The set is composed of all UTF-82 or 7 bit ASCII (American Standard Code for Information Interchange) characters that are allowed in filenames on a particular operating system. 2.3 time sequence data (TSD) file: A TSD file is any type of electronic data file where each data item in the file corresponds to an instant of time that is identified by an explicit or implicit time tag, such as transient data records, event sequences, and periodic data logs. Filenames General A filename is composed of two parts: the first part is the name, and the second part is the extension. The name and extension parts are separated using the dot “.” symbol. The extension is normally used to specify the file type. There are two types of files: the first type is program files such as executables (.EXE) and dynamic link libraries (.DLL), and the second type is user files such as initialization files (.INI), comma separated values (.CSV), and text files (.TXT). Filenames are listed in hidden files called allocation tables. Each entry in the allocation table corresponds to a single file and has several fields, including the filename, the attributes (“A” for archive and “H” for hidden) and the beginning address where the files contents are stored. The old 8.3 style filenames are still the most popular and the most restrictive. The newer operating systems significantly relaxed those 1 The numbers in brackets correspond to those in the bibliography in Annex C. 2 See The Unicode Standard, Version 5.0 B10. 2 Copyright © 2007 IEEE. All rights reserved. IEEE Std C37.232-2007 IEEE Recommended Practice for Naming Time Sequence Data Files restrictions. Filenames on newer operating systems can be up to 253 characters long (11 for the old 8.3 style). 3.2 3.3 Naming conventions for TSD files Several naming conventions are in use today. These formats can be organized in three classes. They are associated, coded, and sequenced. Associated means the filename extension defines the type of data storage format. For example, the extensions “.HDR,” “.CFG,” “.DAT,” and “.INF” are used to indicate that the file contents are compatible with IEEE Std C37.111TM-1999 B6. The nonextension part of an associated filename is totally up to the user. Coded means the filename contains some information about the event. In this case, the storage format is usually manufacturer specific. For example, certain files that are generated from digital fault recorders have the event date and time (up to 12/31/2079-23:59:59.99) and the recorder number (up to 255) coded in the filename. The recorder number is coded in the first two characters of the name, and the date and time are coded in the last nine characters of the filename. The resulting filename is not friendly, and reading it requires special decoding software. For example, “G30BQ1EF.063” is the filename assigned by device number 163 on 09/18/1991 at 14:15:00.630. A detailed example of a similar scheme used to compress over 70 characters of key event information into the old 8.3 filename format is presented in Annex A. The sequenced filenames format is an incremental approach to naming files. This method is valid because t