CJ2 CPU Unit Software User's Manual - CIP ETI

7 File OperationsData File NamesData files do not contain information indicating what data is stored, i.e., what memory area is stored. Besure to give file names that indicate the contents, as shown in the examples below, to aid in file management.Examples: D00100.IOM, CIO0020.IOMData from the beginning of the file will be written starting at the address specified in I/O memory even ifthe data originally written to the data file (IOM, TXT, or CSV) is not from the same area. For example, ifCIO data in a file is written to the DM Area from a Programming Device, the data will be read to the DMArea of the CPU Unit without any indication that the area is different.Additional InformationData files with the TXT and CSV format contain hexadecimal (0 to 9, A to F) data that allows theI/O memory numerical data to be exchanged with spreadsheet programs.ASCII data in I/O memory can be saved as a text file by using the TWRIT(704) (WRITE TEXTFILE) ladder programming instruction or the Memory Card processing function WRITE_TEXT ( )in ST language.Additional InformationThe following illustration shows the binary data structure of a data file (ABC.IOM) containing fourwords from I/O memory: 1234 Hex, 5678 Hex, 9ABC Hex, and DEF0 Hex. The user, however,does not have to consider the data format in normal operations.I/O memoryXXXX1234to56789ABCXXDEF0 123456789ABCDEF048 bytes (used by system)8 bytesContents of ABC.IOM• Structure of CSV and TXT Data Files with Single-word FieldsThe following illustration shows the data structure of a CSV data file (ABC.CSV) with single-wordfields containing four words from I/O memory: 1234 Hex, 5678 Hex, 9ABC Hex, and DEF0 Hex.I/O memory123456789ABCDEF0Convertedto ASCII313233342C353637382Cto1234,5678,4 bytesDelimiter4 bytesDelimiter1234,5678,9ABC,DEF0The file displayed as text.77-3 File Memory Operations7-3-2 File Memory Operating Procedures and File MemoryFilesContents of ABC.CSVCJ2 CPU Unit Software User’s Manual7-17