Siemens SINUMERIK 840D sl Function Manual page 108

Safety Functions Integrated in the System/Drive
6.2 Safe operating stop (SBH)
Note
If "safely-reduced speed" was not active prior to the selection of SBH, any moving
axis/spindle is stopped with STOP B/A.
The actual status of the function is displayed using the SGA "SBH active".
The SGEs and SGAs are described in Section 7.1 "Safety-related input/output
signals (SGE/SGA)".
Internal control request for SBH
When the SG or SE responds (STOP C, D, E) the drive is internally switched to
the safe operating stop state in the control. In such cases, the external circuit of
the SGEs (SBH/SGH de-selection and SBH de-selection) is ignored and both are
internally set to "0".
Selecting SBH from SG
The changeover from safely-reduced speed to safe operating stop is initiated using
the SGE "SBH de-selection". A delay time that is parameterized in the following
machine data is simultaneously started with the changeover to SBH (signal "SBH
de-selection"=0):
with 840D sl
MD 36951: $MA_SAFE_VELO_SWITCH_DELAY
for SINAMICS S120
p9551: SI motion, SG changeover, delay time
SBH is activated as soon as the delay time expires.
Note
If the SBH function is selected while an axis/spindle is moving, the machinery
construction OEM must initiate the braking process such that the axis/spindle is in
position – i.e. stationary – after the delay time has expired. This can be performed
automatically using the "setpoint speed limiting" function. If the axis moves out of
the standstill tolerance window after the delay has expired, an alarm is generated
(for 840D sl: 27010, for SINAMICS S120: F01707) and STOP B/A initiated!
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
© Siemens AG, 2006. All rights reserved
03.06