IEEE C37.111-1999 pdf download IEEE Standard Common Format for Transient Data Exchange (COMTRADE) for Power Systems
1. Overview
1.1 Scope This standard deÞnes a format for Þles containing transient waveform and event data collected from power systems or power system models. The format is intended to provide an easily interpretable form for use in exchanging data. As such, it does not make use of the economies available from data encoding and compres- sion that proprietary formats depend upon for competitive advantage. The standard is for Þles stored on physical media such as digital hard drives and diskettes. It is not a standard for transferring data Þles over communication networks.
1.2 Purpose This standard deÞnes a common format for the data Þles and exchange medium needed for the interchange of various types of fault, test, and simulation data. The rapid evolution and implementation of digital devices for fault and transient data recording and testing in the electric utility industry have generated the need for a standard format for the exchange of data. These data are being used with various devices to enhance and automate the analysis, testing, evaluation, and sim- ulation of power systems and related protection schemes during fault and disturbance conditions. Since each source of data may use a different proprietary format, a common data format is necessary to facilitate the exchange of such data between applications. This will facilitate the use of proprietary data in diverse appli- cations and allow users of one proprietary system to use digital data from other systems.
2. Files and data storage
2.1 Categories of Þles Files stored on digital devices and media consist of bytes representing a combination of alphabetic, numeric, symbol, punctuation, and other formatting characters. Depending on the format, a byte, part of a byte, or more than one byte. may be represented by a letter, number, or symbol (e.g. “A” “3 or “-). There arethree general classes of files used on computer systems: executable files, text files, and data files. The use ofthe file determines the category.
2.1.1 Executable files
Executable files contain a sequence of instructions suitable for processing by a computer. Computer pro-grams are stored as executable files (.EXE). COMTRADE does not define executable files.
2.1.2 Text files
Text files imply data in human-readable form. A text file may be used for control of a computer program ifthe format is rigidly specifed. COMTRADE text files use the character representation specified inANSI X3.4-1986 Bl].’ This is often called “ASCIl formator “Text (TXT) formatby word processolprogramms.
COMTRADE defines one freeform ASCIl text file intended for strictly human interpretation, the Headerfle. COMTRADE also defines three files in which the format is rigidly controlled and which are bothhuman- and computer-readable–the Configuration file and the Information file, and the ASCll form of theData file.
Most word processors can save text files in two or more formats. The text format contains only the charactersactually typed,including punctuation and standard formatting characters such as carriage return/line feedOther formats contain special characters specific to the particular word processor being used. The text for.mat shall be used for the text files in a COMTRADE record to eliminate word processor-specific charactersor codes. Programs intended to read COMTRADE files only require use of the typed characters that mostword processor programs can read or print.
If no command exists in the word processor to save the file in this format, an alternative method is to use theprint functions to print the text to disk to create the file.