A 
 
Appendix  03.04 
B Terms 
 
 
Ó Siemens AG, 2004. All rights reserved 
A-490    SINUMERIK 840D/840Di/810D Operator’s Guide HMI Advanced (BAD) – 03.04 Edition 
   
R 
 
   
R parameter 
Calculation parameter. The programmer can assign or request the 
values of the R parameter in the -> parts program as required (R 
variable). 
 
   
Rail 
This rail is used to mount the modules of the S7-300 system. 
 
   
Rapid traverse 
The highest traversing speed of an axis used, for example, to bring 
the tool from an idle position to the -> workpiece contour or retract it 
from the workpiece contour. 
 
   
Reference point 
Point on the machine tool with which the measuring system of the  
 -> machine axes is referenced. 
 
   
Reference point 
approach 
If the position measuring system used is not an absolute-value 
encoder, then a reference point approach operation is required to 
ensure that the actual values supplied by the measuring system are in 
accordance with the machine coordinate values. 
 
   
Remanence 
Data areas in data blocks, such as timers, counters and flags are 
remanent if their contents are not lost in the case of a restart or Power 
Off. 
 
   
REPOS 
1.  Reapproach contour, triggered by operator 
REPOS allows the tool to be returned to the interrupt position by 
means of the direction keys. 
2.  Programmed contour reapproach 
A selection of approach strategies are available in the form of 
program commands: Approach point of interruption, approach start 
of block, approach end of block, approach a point on the path 
between start of block and interruption. 
 
   
Rigid tapping 
This function is used to tap holes without the use of a compensating 
chuck. The spindle is controlled as an interpolative rotary axis and drill 
axis, with the result that threads are tapped precisely to the final 
drilling depth, for example, in blind tapped holes (precondition: 
Spindle axis mode). 
 
   
Rotary axis 
Rotary axes cause the tool or workpiece to rotate to a specified angle 
position. 
 
   
Rotary axis, 
continuously turning 
The range of motion of a rotary axis can be set to smaller than 360 
degrees or defined as continuous in both directions, depending on the 
application. Continuously turning rotary axes are used, for example, 
for eccentric machining, grinding and winding.