Siemens SINAMICS S120 Function Manual page 409

Application class 3 (positioning drive)
In addition to the drive control, the drive also includes a positioning control, which means that
it operates as a self-contained single-axis positioning drive while the higher-level
technological processes are performed on the controller. Positioning requests are
transmitted to the drive controller via PROFIBUS/PROFINET and launched. Positioning
drives have a very wide range of applications, e.g. the screwing and unscrewing of caps in a
bottle filling plant or the positioning of cutters on a film cutting machine.
Figure 10-3
Application class 4 (central motion control)
This application class defines a speed setpoint interface with execution of the speed control
on the drive and of the positioning control in the controller, such as is required for robotics
and machine tool applications with coordinated motions on multiple drives.
Motion control is primarily implemented by means of a central numerical controller (CNC).
The position control loop is closed via the bus. The synchronization of the position control
cycles in the control and in the closed-loop controllers in the drive requires a clock
synchronization of the kind that is provided by PROFIBUS DP and PROFINET IO with IRT.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Application class 3
Communication PROFIBUS DP/PROFINET IO
10.1 Communication according to PROFIdrive
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