Siemens SINUMERIK 840Di Function Manual page 582

Detailed Description
2.6 Block search Type 5 SERUPRO
Repositioning with controlled REPOS
At any point during processing, a part program can be interrupted and an ASUB started with
a REPOS.
For path axes, the REPOS mode can be controlled by the PLC via VDI signals to reposition
on the contour. This mode is programmed in the part program and defines the approach
behavior. See "Repositioning to contour with controlled REPOS".
The REPOS behavior of individual axes can also be controlled via VDI signals
and is enabled with machine data:
MD11470 $MN_REPOS_MODE_MASK BIT 2==1.
Path axes cannot be influenced individually. For all other axes that are not geometry axes,
repositioning of individual axes can be prevent temporarily and also delayed. VDI signals can
be used to subsequently reenable or to continue blocking individual channel axes that
REPOS would like to traverse.
Danger
Signal:
DB31, ... DBX2.2 (Delete distance-to-go, axis-specific)
produces the following dangerous behavior with "Prevent repositioning of individual axes"
via:
MD11470 $MN_REPOS_MODE_MASK (Bit 2==1).
As long as an axis is programmed incrementally after the interruption, the NC approaches
different positions than those approached with no interruption (see example below).
Example: Axis is programmed incrementally
Axis A is positioned at 11° before the REPOS operation; the programmed operation in the
interruption block (target block for SERUPRO) specifies 27°.
Any number of blocks later, this axis is programmed to move incrementally through 5° with:
N1010 POS[A]=IC(5) FA[A]=1000.
With interface signal:
DB31, ... DBX10.0 (REPOSDELAY)
the axis does not traverse in the REPOS operation and is moved to 32° with N1010.
(The user may have to deliberately acknowledge the travel from 11° to 27°.)
Note:
The axis is programmed incrementally after the interruption.
In the example, the NC moves to 16° (instead of 32°).
2-46
Mode Group, Channel, Program Operation, Reset Response (K1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0