Siemens SINUMERIK 840D sl Function Manual page 498

K1: Mode group, channel, program operation, reset response
9.8 Block search Type 5 (SERUPRO)
Repositioning with controlled REPOS
The REPOS mode can be specified for the path axes via the NC/PLC interface:
DB21, ... DBX31.0 - .2 (REPOS mode A, B, C)
This mode is programmed in the part program and defines the approach behavior (see Section
"Repositioning with controlled REPOS (Page 505)").
The REPOS behavior of individual axes can also be controlled via NC/PLC interface 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,
REPOS of individual axes can be prevented temporarily and also delayed. NC/PLC interface
signals can be used to subsequently re-enable or to continue blocking individual channel axes
that REPOS would like to traverse.
Risk of collision
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°.)
Caution:
The axis is programmed incrementally after the interruption.
In the example, the NC moves to 16° (instead of 32°).
Starting axes individually
The REPOS behavior for SERUPRO approach with several axes is selected with:
MD11470 $MN_REPOS_MODE_MASK BIT 3 == 1
The NC commences SERUPRO approach with a block that moves all positioning axes to the
programmed end and the path axis to the target block.
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DANGER
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions