Safely-Limited Speed (Sls) - Siemens Sinamics S120 Function Manual

4.2.9

Safely-Limited Speed (SLS)

The Safely Limited Speed (SLS) function is used to protect a drive against unintentionally
high speeds in both directions of rotation. This is achieved by monitoring the current drive
speed up to a speed limit.
Safely Limited Speed prevents a parameterized speed limit from being exceeded. Limits
must be specified based on results of the risk analysis. Up to four different SLS speed limits
can be parameterized using parameter p9531[0..3]; it is possible to switch between them
even if the SLS is activated.
An override can also be added to SLS limit value 1. In operation, this override can be varied
using a PROFIsafe telegram.
Not e
Dev iation of the displayed speed limit
The SLS speed limit displayed in r9714[2] can deviate slightly from the specified SLS speed
limit. The reason for this is the internal resolution (r9732) of the speed values.
Not e
Res ponse in t he event of a communication error
If p9580 ≠ 0 and SLS is active, in the event of communication failure, the parameterized
ESR reaction is only realized if, as SLS response, a STOP with delayed pulse cancellation
when the bus fails has been parameterized (p9563[0...3] ≥ 10).
Not e
S et point speed limit and SLS
• It makes sense to configure the set velocity limit if SLS is also parameterized. This is
done in a higher-level controller that evaluates the safety information channel, for
example, or by wiring r9733[0/1] to the speed limits of the ramp-function generator
(p1051/p1052).
• It does not make sense to use the positive and negative setpoint limiting for SLS in
conjunction with standard telegram 105 and others: With this combination, the velocity
setpoint of the standard telegram is only effective after the setpoint limiting.
Safety Integrated
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
99