Slave-To-Slave Communication; Acyclic Communication - Siemens SINAMICS G120 Operating Instructions Manual

Configuring the fieldbus
8.3 PROFIdrive profile for PROFIBUS and PROFINET
8.3.1.4

Slave-to-slave communication

With "Slave-slave communication" ( also called "Data Exchange Broadcast") it is possible to
quickly exchange data between converters (slaves) without the master being directly
involved, for instance to use the actual value of one converter as setpoint for other
converters.
Note
Slave-to-slave communication in the current firmware version is only possible for converters
with PROFIBUS communication.
For slave-to-slave communication, in the control system you must define which converter
acts as publisher (sender) or subscriber (receiver) - and which data or data areas (access
points) you wish to use for slave-to-slave communication. In the converters that operate as
subscriber, you must define how the data transferred using slave-to-slave communication is
processed. Using parameter r2077, in the converter, you can read-out the PROFIBUS
addresses of the converters for which the slave-to-slave communication function is
configured.
● Publisher Slave, which sends the data for slave-to-slave communication.
● Subscriber Slave, which receives the data from slave-to-slave communication from the
● Links and access points define the data that are used for slave-to-slave communication.
You must observe the following restrictions for the slave-to-slave communication function:
● a maximum of 12 PZD are permissible for each drive
● To a publisher, a maximum of 4 links are possible
An example of how you configure slave-to-slave communication between two converters in
STEP 7 is provided in Section: Configuring slave-to-slave communication in STEP 7
(Page 334).
8.3.2

Acyclic communication

8.3.2.1 Acyclic communication
As well as cyclic communication, the converter also offers the option of acyclic
communication for PROFIBUS DP and PROFINET. You can parameterize and diagnose the
converter via acyclic communication. Acyclic communication takes place in parallel with
cyclic communication, but with a lower priority.
The converter supports the following types of acyclic communication:
● Reading and writing parameters via "data set 47" (up to 240 bytes per write or read
● Reading-out profile-specific parameters
● Data exchange with a SIMATIC HMI (Human Machine Interface)
You can find a STEP 7 program example for acyclic data transfer in Section Application
examples (Page 318).
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publisher.
request)
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB