Motion Control With Profibus - Siemens SINAMICS S120 Installation And Start-Up Manual

4.5

Motion control with PROFIBUS

Description
The "Motion control with PROFIBUS" function can be used to implement an iso-
chronous drive link between a master and one or more slaves via the PROFIBUS
field bus.
Note
The isochronous drive link is defined in the following documentation:
References:
Properties
S No additional parameters have to be entered in addition to the bus configuration
in order to activate this function. All that is necessary is to initialize the master
and slave for the function.
S Fixed sampling times are used for all data communication.
S The Global Control (GC) clock information is transmitted before the beginning
of each cycle.
S The length of the clock cycle depends on the drive configuration:
– Large number of drives –> long cycle
– Large number of slaves –> long cycle
S A sign-of-life counter is used to monitor user data transfer and clock pulse
failures.
Overview of closed-loop control
S Sensing of the actual position value on the slave can be performed using:
– An indirect measuring system (motor encoder)
– An additional direct measuring system
S The encoder interface must be configured in the process data.
S The control loop is closed via the PROFIBUS.
S The position controller is located on the master.
S The current and speed control systems and actual value sensing (encoder
interface) are located on the slave.
S The position controller clock cycle is transmitted across the field bus to the
slaves.
S The slaves synchronize their speed and/or current controller cycle with the
position controller cycle on the master.
S The speed setpoint is specified by the master.
E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
/P5/ PROFIdrive Profile Drive Technology
Communication via PROFIBUS
Motion control with PROFIBUS
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