You can open and view the contents of this file using a text editor. What is a PLT file? Plotter file created using the Hewlett-Packard Graphics Language (HPGL); contains a series of two-letter codes, such as 'IP,' which declares the initial point on a plot; may contain optional parameters with the codes; used by various drawing programs and printers for creating printable plotter documents. A standard DPlot file is an ASCII text file containing all of the information DPlot needs to fully reproduce a finished plot. DPlot will also produce compressed DPlot files which contain the same information below but are compressed (and not human-readable) by the ZLIB algorithm. Open the file num2str.m in the Editor. MATLAB opens the file matlabroot toolbox matlab strfun num2str.m. If a file called num2str.m exists in a folder that is above toolbox matlab strfun on the MATLAB path, then MATLAB opens that file instead.

Issue:

Solution:

To open the folder where AutoCAD is looking for plot style files, on the command line in the program, type STYLESMANAGER. All CTB and STB files can be copied here. Keep in mind also that AutoCAD is able to access a plot style file if it is in the same folder as the drawing which uses it.
The default folder locations for plot style files are as follows:
Windows 10, Windows 8, Windows 8.1, Windows 7, Windows Vista:
C:Users&ltuser&gtAppDataRoamingAutodeskAutoCAD 20xxRxx.x&ltlanguage&gtPlottersPlot Styles
Windows XP:
C:Documents and Settings&ltuser&gtApplication DataAutodeskAutoCAD 20xxRxx.x&ltlanguage&gtPlottersPlot Styles
Mac OS:
/Users/&ltuser&gt/Library/Application Support/Autodesk/AutoCAD version Standalone/Rxx.x/roaming/@&ltlanguage&gt@/Plotters/Plot Styles​
These paths can be found within the Options or Preferences of AutoCAD, Windows and Mac OS respectively.

Note: These paths can be edited to a network location for accessing a centralized folder location for plot style files.

Did your computer fail to open a PLT file? We explain what PLT files are and recommend software that we know can open or convert your PLT files.

What is a PLT file?

The .plt file extension is most commonly associated with the Autodesk AutoCAD software application. The PLT files that are used by this software contain vector graphic plotter files that have been created by the applications.
Other applications also use the .plt extension for plotter files, such as the HP Graphics Language and OziExplorer software applications.
PLT files can be printed using a plotter. A plotter draws images using lines instead of printing dots like a normal printer.
The .plt file extension is also used by Bentley's CAD MicroStation application. This application uses the .plt file suffix for plot driver configuration files.

Software that will open, convert or fix PLT files

Try a universal file viewer

In addition to the products listed above, I would suggest that you try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and very likely yours too! Download Free File Viewer.