Lenze i950 Series, Manual

Page: 409 / 500

19.6 Safe Operating Stop (SOS)
In the safe operational stop, the drive is not switched to torque-free operation. All control
functions are maintained. The reached position remains active.
WARNING!
A safety-rated encoder system must be used.
Without an encoder, this safety function cannot be used.
▶
Apply a safety-rated encoder system to use this function.
Preconditions
The drive is brought to standstill via the application.
Functional description
n
t
0
SOS
STO
0x289F:001 0x287B:001
Fig. 72: SOS function
SOS is activated if the motor speed is lower than the tolerance window parameterised in
0x287B:001 0x287B:001, tolerance window (n=0), .
In the SOS state, relative position changes are added and saved in 0x289F:003 0x289F:003 . The
value in 0x289F:003 0x289F:003 is continuously compared to the permissible value in 0x289F:
001 0x289F:001 .
If one of the two states occurs during a safe operational stop (SOS):
•
Position is outside the tolerance window safely monitored in 0x289F:001 0x289F:001
an error message is generated and STO is activated:
When the SOS state is left, the maximum relative positioning is displayed in
0x289F:
003 0x289F:003 .
The 0x289F:002 0x289F:002 parameter defines the restart behaviour after SOS has been deac-
tivated.
If the SOS state is requested again, the sum of the last position changes in
0x289F:003 0x289F:
003 is reset to zero.
Example:
The "SS2 active" state is interrupted by an STO request. If the STO request is reset, the transi-
tion to the SOS state will follow. The position deviation is reset to p = 0.
Activation of the function
The following options are available to activate the function:
•
The Safe Stop 2 (SS2) function
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406
•
The safety bus, see section "Safety bus" .
•
A safe input, see section "Safe inputs"
Behaviour of the function in the event of an error
In the final state "Safe operational stop (SOS)", an error message is triggered if:
•
the speed exits the tolerance window set 0x287B:001 (n=0).
•
the position exits the tolerance window set 0x289F:001 (p=0).
Safety functions
Safe Operating Stop (SOS)
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