Siemens SINUMERIK 840D sl Function Manual page 154

Safety Functions Integrated in the System/Drive
6.5 Safely reduced speed (SG)
Timing when the limit value is exceeded
When the safely reduced speed function is active, then the timing is as follows
when the limit value is violated:
Fig. 6-13
Table 6-13 Explanation of the diagram
Time Explanation
t The position control clock cycle, defined by the following MDs:
1
MD 10050: $MN_SYSCLOCK_CYCLE_TIME
MD 10060: $MN_POSCTRL_SYSCLOCK_TIME_RATIO
t Monitoring clock cycle, defined by the following MDs:
2
for 840D sl:
MD 10090: $MN_SAFETY_SYSCLOCK_TIME_RATIO
for SINAMICS S120:
r9500 SI motion monitoring clock cycle (Control Unit)
t Time between an error occurring and a limit value being reached
3
t Time until a limit value violation is detected
4
(typical 1 monitoring clock cycle, maximum 1.5 monitoring clock cycles + 1 position controller
clock cycle)
t Response time required to initiate the configured stop response
5
(typical 2 monitoring clock cycles, maximum 2.5 monitoring clock cycles + 1 position controller
clock cycle)
t Time until the stop response that was initiated starts
6
(STOP A: typical 2 ms, maximum 3 position controller clock cycles + 8 ms)
(STOP B/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)
6-154
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
n
Limit value
exceeded
b)
SG
Fault
a)
n act
t
3
Timing when the limit value is exceeded for SG
c)
Start of
stop response
t
1
t
2
not to scale
t
t
6
4
t
5
t
7
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05.08
the
t