Setpoint Assignment In The Subscriber; Activating/Parameterizing Slave-To-Slave Communication - Siemens SINAMICS S120 Function Manual

Communication PROFIBUS DP/PROFINET IO
10.2 Communication via PROFIBUS DP
10.2.4.2

Setpoint assignment in the subscriber

Setpoints
The following statements can be made about the setpoint:
● Number of setpoint
● Contents of the setpoints
● Operation as "standard" slave
● Operation as subscriber
10.2.4.3

Activating/parameterizing slave-to-slave communication

The "slave-to-slave communication" function must be activated both in the publishers as well
as in the subscribers, whereby only the subscriber is to be configured. The Publisher is
automatically activated by the bus system when booting.
Activation in the Publisher
The master is informed abut which slaves are to be addressed as publishers with a different
layer 2 function code (DXB request) via the configuration of the subscriber links.
The publisher then sends its input data not only to the master but also as a broadcast
telegram to all bus nodes.
These settings are made automatically by the S7 software.
Activation in the Subscriber
The slave, which is to be used as Subscriber, requires a filter table. The slave must know
which setpoints are received from the master and which are received from a publisher.
STEP7 automatically generates the filter table.
The filter table contains the following information:
● Address of the publisher
● Length of the process data
● Position (offset) of the input data
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When bus communication is being established, the master signals the slave the number
of setpoints (process data) to be transferred using the configuring telegram (ChkCfg).
The structure and contents of the data for the "SINAMICS slave" using the local process
data configuring (p0922).
The drive (slave) only receives its setpoints and output data from the master.
When a slave is operated as a subscriber, some of the setpoints are defined by one or
more publishers rather than by the master.
The slave is informed of the assignment via the parameterization and configuration
telegram when bus communication is being established.
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Drive functions