Siemens SINUMERIK 840D sl Function Manual page 693

Differences between faults and alarms
Faults
Alarms
Fault responses
The standard fault responses according to PROFIdrive, that are used for safety, are described
in the following table. The OFF2 fault response is used as additional stopping measure while
the pulses are safely cancelled via the safety-related switch-off signal paths.
Fault re‐ Response
sponse
OFF2 Internal/external
pulse inhibit
OFF3 Brake along the
OFF3 deceleration
ramp followed by
pulse inhibit
STOP2 n_set = 0
(stop2)
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Type
What happens when a fault occurs?
● The appropriate fault response is initiated.
● Status signal ZSW1.3 is set.
● The fault is entered in the fault buffer.
How are the faults eliminated?
● Remove the cause of the fault.
● Acknowledge the fault.
What happens when an alarm occurs?
● Status signal ZSW1.7 is set.
● The alarm is entered into the alarm buffer.
How are alarms eliminated?
● Alarms are self acknowledging, that is, they are reset automatically when
the cause of the alarm has been eliminated.
● Immediate pulse cancellation, the drive coasts to
standstill.
● The motor holding brake (if parameterized) is
closed immediately.
● Switching-on inhibit is activated.
● The drive is braked along the OFF3 down ramp
(p1135) by immediately entering n_set = 0.
● When zero speed is detected, the motor holding
brake (if parameterized) is closed. The pulses
are cancelled when the brake application time
(p1217) expires.
● Standstill is detected when the actual speed
value is less than the speed threshold (p1226) -
or when the monitoring time (p1227) that started
when speed setpoint ≤ speed threshold (p1226)
has expired.
● The drive is braked along the OFF3 down ramp
(p1135) by immediately entering n_set = 0.
● The drive remains in closed-loop speed control.
11.3 Safety messages for SINAMICS S120
Description
Description
Diagnostics
Safety stop response
STOP A , test stop
STOP B (after r9556 has ex‐
pired or p9560 is fallen below,
STOP A is initiated)
STOP C
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