The syntax for the command line is:
ConvertPPT /S{Original File(s)} /T{Target File(s)} /C# [/Y#] [/Z#] [/E] [/G] [/V] [/R] [/F#] [/L{LogFile}] [/B{LogToJobFile}]
Items above enclosed in square brackets "[ ]" are optional, all other 'switches' are required. Therefore /S, /T, /C# should always be specified on the command line. There is one exception however, and that is when /G is specified, the /T switch is not necessary.
You can include or exclude spaces between switches and parameters. For example, "/C6" is the same as "/C 6".
Command line switches are case sensitive, therefore /V is valid and /v is not.
For long file names (e.g. a path or file name with spaces in it, or longer than 8.3 format) you are required to use double quotes. For example:
ConvertPPT /S "C:\Power Point\1234567891011.ppt" /T "C:\PPTOutput\TextFile.txt" /C200 /V
Next, read about each command line switch and then dive into the examples.
See also:
Complete List of Command Line Examples
Command Line Switch Specification
File Type Constants Specification
Using 'Convert PowerPoint' - Command Line
Helpful Hints For Creating a Command Line