Description Of Stop C - Siemens Sinumerik 840D sl Function Manual

10/15
rpm
n
t
a)
b)
Figure 6-6 Transition from STOP B to STOP A
It is possible that the stop for the NCK becomes effective one safety monitoring
clock cycle earlier than for the drive. This means that braking along the current
limit can become effective before the OFF3 ramp of the drive becomes effective.
In order to reduce the level of stress of the mechanical system of the machine
(if required) the braking torque can be reduced. To realize this, bit 4 "Torque
limiting active in motoring/regenerating mode" can be set in parameter p1400 and
parameter p1521 "Torque limit lower/regenerative" can be set to the required lower
torque. In this case, it should be noted that the braking distance (stopping
distance) of the axis is extended, and that the torque limiting is not only effective
for STOP B, but that generally, the dynamic response of the axis changes.
6.3.4

Description of STOP C

Action in the drive monitoring channel:
The drive is braked along the OFF3 ramp corresponding to the speed setpoint; in
parallel, the timer is started via parameter p9552 "Transition time from STOP C to
SBH". The SBH function is automatically activated after the timer expires.
Action in the NCK monitoring channel:
Essentially the same as the drive, the speed setpoint = 0 is specified by the control
and the interface signal "Position controller active" (DB31, ... DBX61.5) of the drive
involved is set to zero.
In parallel, the timer is started using MD36952
$MA_SAFE_STOP_SWITCH_TIME_C.
The SBH function is automatically activated after the timer expires.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
ac
b)
a)
Shutdown speed,
pulse cancellation
STOP B
Delay time, pulse
cancellation
STOP B
STOP B
Safety functions integrated in the system/drive
a) Shutdown time is reached before the
pulse cancellation delay time expires
b) Shutdown time is reached after the
pulse cancellation delay time expires
STOP A
STOP A
STOP A
6.3 Safe Stops A- -F
t
6-133