Siemens Sinumerik 840D sl Function Manual page 174

Safety functions integrated in the system/drive
6.7 Safe software limit switches (SE)
Table 6-20 Explanation of the figure
Time Explanation
t The position control clock cycle, defined by the following MDs:
1
for 840D sl:
MD10050 $MN_SYSCLOCK_CYCLE_TIME
MD10060 $MN_POSCTRL_SYSCLOCK_TIME_RATIO
t Monitoring clock cycle, defined by the following MDs:
2
for 840D sl:
MD10090 $MN_SAFETY_SYSCLOCK_TIME_RATIO
for SINAMICS S120:
p9500 SI Motion monitoring clock cycle (Control Unit)
t Delay until the configured stop response is output
3
(typical 0.5 monitoring clock cycles, maximum 1 monitoring clock cycle + 1 position controller
clock cycle)
t Time until the configured stop response becomes effective
4
(typical 1.5 monitoring clock cycles, maximum 2 monitoring clock cycles + 1 position controller
clock cycle)
t Time until the stop response that was initiated actually starts
5
STOP C: typical 2 position controller clock cycles, maximum 2 position controller clock cycles
STOP D/E: typical 2 interpolation clock cycles, maximum 2 interpolation clock cycles + 2 moni-
toring clock cycles
t Time required to bring the axis to a standstill.
6
This time and thus the residual distance traveled by the axis is determined by the axis design
(motor, mass, friction, ...) and the configured stop response (STOP C is faster than STOP D).
Note:
Each axis must be measured during commissioning (start--up) to determine the distance that it travels
between the limit switch being violated and it coming to a standstill.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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