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

05.08
RPM
n
act
a)
b)
Fig. 6-6
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 parame-
ter 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.
6.3.4

Description of STOP C

Action in the drive monitoring channel:
The drive is braked along the STOP2 ramp in response to a speed setpoint input =
0 and in parallel, the timer via parameter p9552: "Transition time from STOP C to
SBH" is started. The SBH function is automatically activated after the timer ex-
pires.
Action in the NCK monitoring channel:
Essentially the same as in the drive, the control specifies a zero speed setpoint
and the interface signal "position controller active" (DB 31, ... DBX 61.5) of the as-
sociated drive is set to zero.
At the same time, the timer via MD 36952: $MA_SAFE_STOP_SWITCH_TIME_C
is started. The SBH function is automatically activated after the timer expires.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
b)
a)
Shutoff speed for
pulse suppression
STOP B
Delay time, pulse
cancellation
STOP B
STOP B
Transition from STOP B to STOP A
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
6-135