Function "Synchronization, Hysteresis And Filtering N<Nx - Siemens SINUMERIK 840D sl Function Manual

Safety functions integrated in the system/drive
7.6 Safe speed range detection "n<nx"
Response time and error responses
Typical response time for n<n
1 interpolation clock cycle + 2 monitoring clock cycles
Maximum response times: 1 position controller clock cycle + 5.5 monitoring clock cycles + 2
interpolation clock cycles + 3 PLC cycles
n<n
A STOP F (displayed using Alarms 27001, 27101 and onwards or F01711) only results in a
subsequent STOP B/A response, if at least one of the safety-related functions SBH, SG, SE,
SN or n<n
F does not result in a subsequent STOP B/A response.
This means that if "n<n
or SN functions must be active or selected (e.g. by selecting a high SG level).
Note
If the axis/spindle runs at a speed n
channels, the SGA "n<n
This must be taken into account in the safe processing of the SGA.
7.6.2 Function "Synchronization, hysteresis and filtering n<nx"
As a result of actual value differences (2-encoder system) in the two monitoring channels,
static or dynamic differences can occur at the SGA "n<n
externally further process the signals. This is the reason that the "n<n
monitoring channels associated with the NCK and the drive are synchronized before further
processing.
In addition, a hysteresis is implemented to prevent the SGA "n<n
as a result of slight speed fluctuations around the threshold "n
for example caused by mechanical vibration at the machine, SGA "n<n
filtering the speed actual value.
In order to be able to use the "Synchronization, hysteresis and filtering" function, bit 16 must
be set in machine data $MA_SAFE_FUNCTION_ENABLE. The specified three functions can
only be enabled together. Further, the speed monitoring function n<n
by a value greater than 0.0
For 840 D sl:
MD36946 $MA_SAFE_VELO_X
For SINAMICS S120:
p9546 SI Motion SSM (SGA n < n
The following diagram shows possible different speed characteristics in the NCK and drive,
and the effect of synchronization and hysteresis on the SGA "n<n
150
WARNING
as safety function
x
synchronization is active or selected. If only function "n<n
x
" is used as a safety function, then at least one of the SBH, SG, SE
x
" can have a different state.
x
:
x
, then as a result of actual differences in the two monitoring
x
) speed limit (CU)
x
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
" is active, then a STOP
x
", which makes it very difficult to
x
" signals of the two
x
" from continually switching
x
". For actual value fluctuations,
x
" is kept stable by
x
must always be activated
x
".
x
Safety Integrated