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
5.10.3
Activating/parameterizing slave–to–slave communications
The ”slave–to–slave communications” function must be activated both
in the publishers as well as in the subscribers.
By configuring the links with Drive ES Basic, the master can identify
which slaves are to be addressed as publisher with a modified layer 2
function code (DXB request).
The publisher then does not send its input data to the master, but to all
bus nodes as broadcast telegram.
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.
The filter table contains the following information:
From which publisher is data to be retrieved?
The length of the publisher input data (test purposes)?
From which position (offset) in the input data is data to be taken?
How much data is to be taken?
To which position in the setpoints is the data, which has been taken,
to be copied?
Parameterizing telegram (SetPrm)
The filter table is transferred, as dedicated block from the master to the
slave with the parameterizing telegram when bus communications are
established.
If:
The block for the filter table is not available
or
element ”number of links” = 0
Then:
––> no subscriber functionality
The precise structure of this block, together with the permissible setting
values is shown in Fig. 5-32.
Configuration telegram (ChkCfg)
Using the configuration telegram, a slave knows how may setpoints are
to be received from the master and how many actual values are to be
sent to the master.
For slave–to–slave communications, a special empty ID is required for
each data access, which is then transferred with the ChkCfg.
Structure of the empty ID for Drive ES Basic (S7 ID format):
0x04 0x00 0x00 0xD3 0x40
Activation in the
publisher
Activation in the
subscriber
5 Communications via PROFIBUS DP
08.99
07.01
08.01