Siemens SINUMERIK 840D sl Function Manual page 156

Safety functions integrated in the system/drive
7.7 Safe software limit switches (SE)
Effect
● The configured stop response is initiated
● The relevant alarm is displayed
Acknowledging and retracting
1. Withdraw the user agreement (SE is no longer active) or changeover to another SE.
2. Acknowledge the stop and alarm response.
3. Bring the axis into a range in which the monitoring no longer responds.
Timing when the safe software limit switches are actuated
If the "safe software limit switches" function is active, the system timing is as follows when the
software limit switches are actuated (passed):
Figure 7-18
Table 7-11 Explanation of the diagram
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 MD:
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)
156
Timing when a software limit switch is actuated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated