Steam functions naming convention

Steam property functions follow a consistent naming convention and return digital states when input values are invalid or calculations fail. Use this section to understand how the functions are named and what their outputs mean.

• Function prefixes

  • STMENG_XXX: Functions that use English units.

  • STMSI_XXX: Functions that use SI units.

• Function behavior

  • Each function returns a steam property value.

  • All functions accept real numbers as input arguments (type R).

• Digital states

  • INP OUTRANGE: The input condition is outside the valid computation range.

  • NOT CONVERGE: The calculation failed to converge during iteration.

These digital states are standard and are installed with the PI Data Archive.

For details about each formula’s format, see Steam functions reference.