Siemens SINUMERIK 840D sl Function Manual page 140

Safety functions integrated in the system/drive
7.5 Safely reduced speed (SG)
The required speed limit is selected as follows by combining the following SGEs:
SG selection
bit 1
= 0
= 0
= 1
= 1
Note:
SG limit values SG2 and SG4 can be more finely graduated using the SG override (see Chapter
1)
"Override for safely reduced speed (Page 144)"). The active SG stage is displayed using SGA "SGA
active bit 0" and "SGA active bit 1".
Changing over speed limits
A changeover from a lower to a higher speed limit value takes effect instantaneously without
any delay.
When changing-over from a higher to a lower limit value, then a delay time is started that is
parameterized using the machine data (see diagram "Timing when changing-over from a
higher to a lower speed limit value").
For 840D sl
MD36951 $MA_SAFE_VELO_SWITCH_DELAY
For SINAMICS S120
p9551 SI Motion SLS(SG) changeover delay time (Control Unit)
The axis/spindle must be braked sufficiently during the delay time so that it has reached the
reduced speed that is below the new limit value when the delay time expires. However, if the
actual speed is higher than the new limit value when the time has expired, an appropriate alarm
is output with the configurable stop response.
140
SGE
SG selection
bit 0
= 0 Speed limit value for SG1 active
= 1 Speed limit value active for SG2
= 0 Speed limit value for SG3 active
= 1 Speed limit value active for SG4
Meaning
1)
1)
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated