The value of prtInterpreterIndex corresponding to the
Control Language Interpreter for this channel. This
interpreter defines the syntax used for control
functions, such as querying or changing environment
variables and identifying job boundaries (e.g. PJL,
PostScript, NPAP). Must be 1 or greater.
Additional information:
This object points to the PJL language. It is
read-only because PJL (2) is the printer's only job
control language.