Siemens Sinamics S120 Function Manual page 507

Application class 2 (standard drive with technology function)
The total process is subdivided into a number of small subprocesses and distributed among
the drives. This means that the automation functions no longer reside exclusively in the
central automation device but are also distributed in the drive controllers.
Of course, this distribution assumes that communication is possible in every direction, i.e.
also cross-communication between the technology functions of the individual drive
controllers. Specific applications include setpoint cascades, winding drives, and speed
synchronization applications for continuous processes with a continuous web.
M
Figure 10-2
Drive functions
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
M
Application class 2
10.1 Communication according to PROFIdrive
M
Communication
505