Diagnosing Profibus Slave-To-Slave Communication - Siemens SINAMICS S120 Series Function Manual

Communication via PROFIBUS DP
4.5 Messages via diagnostics channels
4.4.4

Diagnosing PROFIBUS slave-to-slave communication

Since the PROFIBUS slave-to-slave communication is implemented on the basis of a
broadcast telegram, only the subscriber can detect connection or data faults, e.g. via the
publisher data length (see "Configuration telegram").
The publisher can only detect and report an interruption of the cyclic connection to the DP
master (A01920, F01910). The broadcast telegram to the subscriber will not provide any
feedback. A fault of a subscriber must be fed back via slave-to-slave communication. In case
of a "master drive" 1:n, however, the limited quantity framework (see "Links and requests")
should be observed. It is not possible to have n subscribers report their status via slave-to-
slave communication directly to the "master drive" (publisher).
Diagnostics can be performed using the diagnostic parameters r2075 ("Receive PROFIBUS
diagnostics telegram offset PZD") and r2076 ("Send PROFIBUS diagnostics telegram offset
PZD"). The parameter r2074 ("PROFIBUS diagnostics, receive bus address PZD") displays
the DP address of the setpoint source of the respective PZD.
r2074 and r2075 enable the source of a slave-to-slave communication relationship to be
verified in the subscriber.
Note
The subscribers do not monitor the existence of an isochronous publisher sign-of-life.
Faults and alarms with PROFIBUS slave-to-slave communication
The alarm A01945 signals that the connection to a least one publisher of the drive device is
missing or has failed. Any interruption to the publisher is also reported by the fault F01946 at
the affected drive object. A failure of the publisher only impacts the respective drive objects.
More detailed information on the messages can be found in the SINAMICS S120/S150 List
Manual.
4.5 Messages via diagnostics channels
Messages are not just able to be displayed via the Startdrive commissioning tools. After the
activation of a diagnostic function, the messages are also transferred to the higher-level
controller via the standardized PROFIdrive fault classes. The messages are evaluated there
or forwarded for convenient display to the corresponding user interfaces (SIMATIC HMI, TIA
Portal, etc.).
In this way, problems or faults can be located immediately regardless of the tool currently
being used, and then corrected immediately.
Also note the general information on the diagnostics channels in Section Diagnostics
channels (Page 66).
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Function Manual, 12/2018, 6SL3097-5BD00-0BP0
Communication