Siemens Sinumerik 840D sl Programming Manual page 191

Axis/spindle replacement
An axis/spindle is permanently assigned to a specific channel via machine data. This
assignment via machine data can be reset with program commands and the axis/spindle can
be assigned to another channel.
Backlash compensation
Compensation of the mechanical backlash of the machine, e.g. the backlash compensation
of the spindles. The backlash compensation can be input separately for each axis.
Backup
A copy of the memory contents (hard disk) stored on an external device for the purpose of
data backup/archiving.
Base axis
Axis whose setpoint value or actual value is used in the calculation of the offset value.
Basic coordinate system
Cartesian coordinate system which is mapped through a transformation onto the machine
coordinate system.
The programmer works in the -> part program with the axis names of the basic coordinate
systems. The basic coordinate system exists in parallel to the -> machine coordinate system,
if no -> transformation is active. The difference between the two systems lies only in the axis
identifiers.
Baud rate
The speed at which the data transfer takes place (bit/s).
Block search
The block search function can be used to go to any convenient point in a part program at
which the machining is to start or continue. This function is intended for testing the part
programs or for continuing the machining after an interruption.
Booting
Loading the system program after power on.
B-spline
The points programmed for the B spline are not interpolation points but simply "checkpoints".
The generated curve only runs near the checkpoints, not directly through them (optional 1st,
2nd or 3rd order polynomials).
ISO Milling
Programming Manual, 06/09, 6FC5398-7BP10-1BA0
Glossary
191