Siemens Sinumerik 840D sl Function Manual page 136

Safety functions integrated in the system/drive
6.3 Safe Stops A- -F
For spindles, the actual acceleration characteristic is not adapted. The control
checks whether the braking time, set in MD36953
$MA_SAFE_STOP_SWITCH_TIME_D, is sufficient for all spindle operating
modes and configured gear stages. When violated, suppressible alarm 22002
"Channel %1 Spindle%2: Braking ramp longer than STOP D time. Gearbox
stage %3. Reason: %4 has been output. If the spindle is in axis operation, then
it behaves just like an axis.
For an active axis or spindle coupling (with the exception of the synchronous
spindle coupling), the coupling is no longer taken into consideration, if synchro-
nous stopping of the coupled group is no longer safely possible within the time
parameterized in MD $MA_SAFE_STOP_SWITCH_TIME_D. For a coupled
group, this is the reason that for all axes of the coupled group, a STOP D must
be set.
For the synchronous spindle coupling, when synchronous operation is reached,
the coupling is always maintained. The coupling group is always braked via the
leading spindle. If the following spindle requires a longer braking time than the
leading spindle, then MD $MA_SAFE_STOP_SWITCH_TIME_D must be
appropriately increased for the leading spindle.
When a synchronous spindle is active, STOP D should also be initiated for the
leading and following spindle.
Endlessly rotating axes are braked at the acceleration limit. The SBH function is
automatically activated after the timer expires.
When Alarm 22001/22002 is output, the following formulas are applied:
METRIC: SAFE_STOP_SWITCH_TIME_D > MAX_AX_VELO * 1/60000 / MAX_AX_ACCEL
INCH/ROT/ SAFE_STOP_SWITCH_TIME_D > MAX_AX_VELO * 1/60 / MAX_AX_ACCEL
SPINDLE:
For axes with jerk limitation, the minimum braking time is increased by the addi-
tional component:
2 * MAX_AX_ACCEL / MAX_AX_JERK
The check is made for NEWCONF, RESET, unparking an axis and for pro-
gramming ACC or JERKLIM.
The MD names contained in the formulas must, corresponding to the alarm
situation (the alarm occurs when parameterizing or when programming) may
have to be replaced by other values.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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