Siemens Sinamics s120 Commissioning Manual page 66

Preparation for commissioning
2.5 System rules, sampling times and DRIVE-CLiQ wiring
Note
The speed controller cycle is assigned automatically when the current controller cycle is set:
• Servo control: Speed controller cycle = current controller cycle
• Vector control: Speed controller cycle = current controller cycle x 4
The preassignment of the speed controller cycle can be changed to influence T
example, the current controller cycle can be increased from 800 µs to 1000 µs so that T
can be set to be a multiple of 1000 µs.
Asynchronous node on the isochronous PROFIBUS
For cycle mix, lengthened base cycles with the following effects often result on the
isochronous PROFIBUS:
● Because the isochronous PROFIBUS can no longer be operated with the default setting,
adaptations must be made to the hardware configuration.
● The increased setting values for T
dynamics of the position control loop.
Despite a cycle mix, the parameter p2049 can be used to operate the axis with the different
current controller cycle asynchronously on the isochronous PROFIBUS. This allows the
default setting of the hardware configuration to be retained.
This, however, causes the advantages of the isochronous operation for the asynchronous
axis to be lost:
● The setpoints act at times that differ from T
operation with other axes is not possible.
● The actual values are read at times that differ from T
used to control other axes.
A critical application would be, for example, a spindle that cuts a thread with the
programmed thread pitch together with a position-controlled Z-axis by the controller
adjusting the plunging depth of the Z-axis depending on the spindle position.
66
, T and T have disadvantageous effects on the
i o dp
, i.e. an interpolating position-controlled
o
, i.e. the actual values must not be
i
Commissioning Manual, (IH1), 07/2016, 6SL3097-4AF00-0BP5
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mapc
mapc
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