Siemens SINUMERIK MC Commissioning Manual page 186

Safety functions integrated in the drive
4.17 SLA
Once selected, the SLA function becomes immediately active without any delay.
You can use telegrams 30, 31, 901, 902 and 903 for SLA. These telegrams contain the control
words S_STW1.8 and S_STW2.8 and status words S_ZSW1.8 and S_ZSW2.8 for SLA.
Acceleration limit
● You define the acceleration limit to be monitored using parameter p9578. This limit value is
applicable for both the positive and negative directions of rotation.
● When setting p9578, the following rule must be complied with:
– p9578 ≥ 10 · r9790[1]
● The possible acceleration resolution is shown by the drive in r9790:
– r9790[0] = resolution, coarse
– r9790[1] = resolution, fine
The actual accuracy of the acceleration detection depends on the type of actual value
acquisition, the gear ratios as well as the quality of the encoder being used.
● The drive indicates the velocity limit corresponding to the actual acceleration in r9714[3].
● r9789 allows the finer resolution acceleration monitoring to be diagnosed. Index 0 indicates
the actual acceleration determined. Index 1 and 2 indicate the current limit values of the SLA
monitoring.
Filter time
If the determination of the acceleration leads to very noisy signals, the drive cannot reasonably
monitor the acceleration.
Remedy
● In this case, increase the "SLA filter time" (p9576).
Note that SLA reacts with a delay when you increase the filter time.
Stop response
If the SLA subsequently detects violation of the acceleration limit, the drive initiates the stop
response configured using p9579.
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Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB