Siemens SINUMERIK 840D sl Function Manual page 567

Behavior when the single-block processing is set
The following channel-specific machine data is used to set for each interrupt signal whether
the assigned ASUBs are processed without interruption with active single-block processing or
whether the single-block processing is to apply:
MD20117 $MC_IGNORE_SINGLEBLOCK_ASUP, bit 0 - bit 31
Bit x is assigned to the interrupt signal (x+1).
Supplementary conditions
● MD20117 $MC_IGNORE_SINGLEBLOCK_ASUP only applies for IPO single block (SBL1).
● The settings in MD20117 $MC_IGNORE_SINGLEBLOCK_ASUP have no effect if the
single-block processing in the ASUB is always to be ignored:
MD10702 $MN_IGNORE_SINGLEBLOCK_MASK, bit 1 = 1
Suppressing the updating of the "Program and channel state" display
To avoid a flickering of the display of the program and the channel states on the user interface
when executing a very short ASUB, the updating of the display can be suppressed. The
program and channel state before activation of the ASUB is then displayed. The parameter
assignment is performed via channel-specific machine data:
MD20191 $MC_IGN_PROG_STATE_ASUP, bit 0 - bit 31
Bit x is assigned to the interrupt signal (x+1).
The following NC/PLC interface signal is set when executing an ASUB with suppressed display:
DB21, ... DBX378.1 == 1 (still ASUB active)
Special system variables and NC/PLC interface signals
The system variables and NC/PLC interface signals for the program state and the channel
state are not affected by the suppression of the display during the execution of an ASUB:
● $AC_STAT (channel state)
● $AC_PROG (program state)
● DB21, ... DBX35.0 - 4 (program state)
● DB21, ... DBX35.5 - 7 (channel state)
Fast retraction from contour (LIFTFAST)
The following machine data can be used to set whether the retraction direction for "Fast
retraction from the contour" (LIFTFAST) is to be mirrored when the "Mirror" function is active:
MD21202 $MC_LIFTFAST_WITH_MIRROR (fast retraction with mirroring)
The mirroring of the retraction direction only refers to the direction components perpendicular
to the tool direction.
References
A detailed description of the machine data can be found in:
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
K1: Mode group, channel, program operation, reset response
9.10 Asynchronous subprograms (ASUBs), interrupt routines
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