Data File Overview

A Gamry Framework™ data file is a standard “tab-delimited” ASCII file. By default it has a *.DTA filename extension. You may use other filename extensions, but they are less convenient.

You can use the Windows^® Notepad to examine and modify Gamry Framework data files, but with some care. Microsoft Excel^® can also read these data files, and can view or print them. However, editing and saving a file using Microsoft Excel may render the file unreadable by the Gamry Echem Analyst™.

The data file is a collection of data objects. Each data object starts on a new line and is identified by a type, a tag, and one or more values. The type is a text descriptor of the kind of object represented by this information. Any text at the beginning of a line is assumed to be a type identifier. The data objects can be of various types. The type, tag, and values of a data object are separated by the tab character.

After each type identifier, there is a tag identifier, which is a unique name for a specific object. Setup parameter data objects may also have one or more values following the type and tag .

The first two lines of a Framework data file are generally two special and important data objects.

EXPLAIN

TAG EXPERIMENT TYPE

The EXPLAIN type identifies this file as one output from an Explain™ script. Without this line, the Gamry Echem Analyst cannot read in a file.

The next line begins an object, uniquely identified as type TAG, that is used to specify which experiment created the data file. In this example, the tag is EXPERIMENT TYPE. The Gamry Echem Analyst uses this object to determine which Analysis script to use when this data file is opened. Data objects are generally more complicated. In the following example, the object is of type POTEN, and stores information about a potential. The tag or name of this object is VINIT. The information about POTEN is contained in the three fields that follow the tag. The tab character is represented by <tab> so you do not confuse it with the space character.

POTEN<tab>VINIT<tab>-5.00000E-001<tab>F<tab>Initial&E(V)

One special type is a TABLE. A TABLE is output by a data curve. The tag for a data curve is followed by the number of data points. The table headings, units, and data values follow on subsequent lines. The table headings and units help to identify the data that is stored in a column. In the example below, the fourth column stores the measured current (Im) and the unit used to store the data is the ampere (A = ampere). The current stored for the third point is about -1.13×10-4 A, or 113 µA.

TABLE CURVE 21

Pt T Vf Im Vu Sig Ach Over

# s V A V V V bits

0 0.99998 -4.98000E-001 -2.06420E-004 0.00000E+000 -5.00000E-001 1.54350E+000 ………….

1 1.99995 -4.49000E-001 -1.56950E-004 0.00000E+000 -4.50000E-001 1.54350E+000 ………….

2 2.99993 -3.98000E-001 -1.31810E-004 0.00000E+000 -4.00000E-001 1.54350E+000 ………….

3 3.9999 -3.49000E-001 -1.13670E-004 0.00000E+000 -3.50000E-001 1.54360E+000 ………….

Fields (types, tags, and values) within data objects are separated by the <TAB> character. One exception is the separator between data points in a data curve, which is a carriage return. Data objects can appear in any order in the file. The Gamry Echem Analyst locates objects within the file by means of their tags.