Siemens SINUMERIK 840D sl Programming Manual page 654

Glossary
Global main program/subroutine
Every global main program/subroutine can only appear once under its own name in the
directory, and it is not possible to have the same program name in different directories with
different contents as a global program.
Ground
Ground is taken as the total of all linked inactive parts of a device which will not become live
with a dangerous contact voltage even in the event of a malfunction.
Helical interpolation
Helical interpolation is especially suitable for easy machining inside or outside threads with
form cutters and for milling lubricating grooves.
The helix consists of two motions:
• A circular movement in one plane
• A linear movement perpendicular to this plane
High-level CNC language
The high-level language offers: -> User-defined variable, -> System variable, -> Macro
technique.
High-speed digital inputs/outputs
Digital inputs can be used to start high-speed CNC program routines (interrupt routines), for
example. The digital CNC outputs can be used to trigger fast, program-controlled switching
functions (SINUMERIK 840D).
HIGHSTEP
Summary of the programming options for the -> PLC in the AS300/AS400 system.
I/O module
I/O modules represent the link between the CPU and the process.
I/O modules are:
• → Digital input/output modules
• → Analog input/output modules
• → Simulator modules
Inch system
Measuring system that defines distances in inches and fractions of inches.
Glossary-8
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
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