Siemens Sinumerik 840D sl Programming Manual page 200

Glossary
Machining channel
The channel structure can be used to reduce downtime by executing motional sequences
simultaneously. Thus, for instance, the gantry of a loader can execute its movements during
the machining. In this case, the CNC functions as an autonomous control system, which
performs operations like decoding, block preparation and interpolation independently.
Macros
Several instructions in different programming languages can be combined with each other in
one instruction. This abbreviated sequence of instructions is called in the CNC program
under a user-defined name. The instructions are executed one after the other with the
macro.
Main block
A block that is preceded by a ":" sign and that contains all the parameters necessary for
starting the processing of a -> part program.
Main program
A -> part program that is denoted by a number or a name in which other main programs,
subprograms or -> cycles can be called.
Main run
Part program blocks that have been decoded and prepared via block preparation, are
processed in the "main run".
MDA
Control operating mode: Manual Data Automatic = manual date input in automatic mode.
Individual program blocks or block sequences with no reference to a main program or
subprogram can be input in MDA mode; these are processed immediately on actuating the
NC start key.
Memory reset
The following -> CPU memories are erased by a memory reset operation:
● -> Work memory
● Read/write area of the -> load memory
● -> System memory
● -> Backup memory
Metric or inch dimensions
Position and thread leads values can be programmed in the machining program in inches.
The control is always set to the basic system independently of the programmed unit of
measurement (G70/G71).
200
Programming Manual, 06/09, 6FC5398-7BP10-1BA0
ISO Milling