5
5.10 Slave–to–slave communications (from SW 4.1)
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SIMODRIVE 611 universal Description of Functions (FBU) – 04.05 Edition
5.10
Slave–to–slave communications (from SW 4.1)
5.10.1
General information
For PROFIBUS–DP, the master addresses all of the slaves one after
the other in a DP cycle. In this case, the master transfers its output
data (setpoints) to the particular slave and receives as response the
input data (actual values).
Fast, distributed data transfer between drives (slaves) is possible using
the ”slave–to–slave” communications function without involving the
master.
The following terms are used for the functions described here:
Slave–to–slave communications
Data exchange broadcast (DXB.req)
Slave–to–slave communications (is used in the following)
A
DP master Class 1
(e.g. SIMATIC S7)
Parameterizing master
Clock cycle generator
B
Response
Input data
1)
Output data
1)
1) From the perspective of the Class 1 master
DP slave
611U
Publisher
A
B
DP slave
611U
Subscriber
A
B
DP slave
611U
Subscriber
Links
PG/PC
Engineering
HW Config
Drive ES Basic
Fig. 5-30 Slave–to–slave communications with the publisher–subscriber
module
For the ”slave–to–slave communications” function, at least one slave
must accept the role of publisher.
The master addresses the publisher, when transferring the output data,
with a modified Layer 2 function code (DXB.req). The publisher then
sends its input data to the master with a broadcast telegram to all bus
nodes.
Description
Publisher
5 Communications via PROFIBUS DP
08.99
07.01
08.01
