Nc-Controlled Retraction - Siemens SINUMERIK 840D sl Function Manual

6.2.5

NC-controlled retraction

Parameter assignment
NC-controlled retraction is parameterized with:
MD37500 $MA_ESR_REACTION = 21
Behavior
If the channel-specific system variable $AC_ESR_TRIGGER = 1 is set, and if there is a
retraction axis in this channel and $AA_ESR_ENABLE=1 is set for this, then LIFTFAST is
activated in this channel.
Precondition
The retraction position must have been programmed in the part program. The enable signals
must be set and remain set for retraction motion.
Rapid lift to the position defined with POLF is triggered using the modal program command
LFPOS (46th G code group).
The retracting movement configured with LFPOS, POLF for the axes selected with POLFMASK
or POLFMLIN replaces the path motion defined for these axes in the parts program.
During retraction:
• The axes defined in POLFMASK independently travel to the positions specified with POLF.
• The axes defined in POLFMLIN travel to the positions specified with POLF in a linear
relationship.
The extended retraction (i.e. LIFTFAST/LFPOS initiated through $AC_ESR_TRIGGER )
cannot be interrupted and can only be terminated prematurely using EMERGENCY OFF.
Speed and acceleration limits for the axes involved in the retraction are monitored during the
retraction motion. The retracting movement takes place with BRISK, i.e. without jerk
limitation.
The maximum time available for retraction is the sum of the following delay times:
• MD21380 $MC_ESR_DELAY_TIME1 (delay time, ESR axes)
• MD21381 $MC_ESR_DELAY_TIME2 (delay time, ESR axes)
After the delay time has expired, fast braking is also initiated for the retraction axis with
subsequent tracking.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
R3: Extended stop and retract
6.2 Control-managed ESR
369