Supplementary Conditions - Siemens SINUMERIK 828D Function Manual

18.5.4.5

Supplementary conditions

Supplementary conditions
• Any further NC commands (e.g., auxiliary function outputs, synchronous axis movements, positioning axis
movements, etc.) can be programmed in a SAR block.
These are executed in the first subblock on approach and in the last subblock on retraction.
• If the end point P is taken not from the SAR block but from a subsequent traversing block, the actual SAR
4
contour (straight line, quadrant or semicircle) is traversed in this block.
The last subblock of the original SAR block does not then contain traversing information for geometry axes. It
is always output, however, because further actions (e.g., single axes) may have to be executed in this block.
• At least two blocks must always be taken into consideration:
- The SAR block itself
- The block, which defines the approach or retraction direction
Further blocks can be programmed between these two blocks.
The number of possible dummy blocks is limited with the machine data:
MD20202 $MC_WAB_MAXNUM_DUMMY_BLOCKS (Maximum number of blocks with no traversing motions
with SAR).
• If tool radius compensation is activated simultaneously in an approach block, the first linear block of the SAR
contour is the block, in which activation takes place.
The complete contour generated by the SAR function is treated by tool radius compensation as if it has been
programmed explicitly (collision detection, calculation of intersection, approach behavior NORM/KONT).
• The direction of the infeed movement and the position of the circle plane or the helix axis are defined
exclusively by the active plane (G17 - G19) - rotated with an active frame where appropriate.
• On approach, a preprocessor stop must not be inserted between the SAR block and the following block,
which defines the direction of the tangent.
Whether programmed explicitly or inserted automatically by the controller, a preprocessor stop results, in this
case, in an alarm.
Response with REPOS
If an SAR cycle is interrupted and repositioned, it resumes at the point of interruption on RMI. With RME, the
contact point is the end point of the last SAR block; with RMB, it is the start point of the first SAR block.
If RMI is programmed together with DISPR (reapproach at distance DISPR in front of interruption point), the
reapproach point can appear in a subblock of the SAR cycle before the interruption subblock.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
18.5 Tool radius compensation 2D (TRC)
W1: Tool offset
1475