Supplementary Conditions - Siemens SINUMERIK 840D sl Function Manual

Connecting sensors and actuators
8.6 Safe Brake Test (SBT)
8.6.9

Supplementary conditions

● When testing the mechanical braking system, it is not permissible that traverse to fixed stop
(FXS) and traversing with a limited torque, FOC are simultaneously active. In this case,
Alarm 20092, "Axis %1 travel to fixed stop still active" is triggered.
● During the brake test, contour monitoring is not active. After the PLC has started traversing
motion then there is also no standstill monitoring.
● For a gantry or master/slave group, the machinery manufacturer (OEM) must decide on a
case-for-case basis whether a defective brake could result in mechanical damage. The
brake test should not be performed if mechanical damage could occur.
● For other "travel to fixed stop" applications, machine data MD37050
$MA_FIXED_STOP_ALARM_MASK and MD37052
$MA_FIXED_STOP_ALARM_REACTION should be adapted.
● If FC18 is called for the same axis in the remainder of the user program, the calls must be
mutually interlocked. For example, this can be achieved via a common call of this function
with an interlocked common data interface for the FC18 parameters. An additional option
is to call the FC18 a multiple number of times, in which case the inactive FC18 must be
skipped. An interlock against being used a multiple number of times must be provided.
308
Torque limit when testing the SBT
Reduction of the torque limit – at the end of the
test, the limit is set to 0 in order to decrease the
additionally generated torque to zero.
Required torque when testing the SBT
During the test, an additional torque is built up
and reduced again at the end.
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated