Diagnosing The Profibus Slave-To-Slave Communication In Starter - Siemens SINAMICS DCM Operating Instructions Manual

Descriptions of functions
10.2 PROFIBUS
10.2.8.5

Diagnosing the PROFIBUS slave-to-slave communication in STARTER

Diagnostics
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)!
For diagnostic purposes, there are the diagnostic parameters r2075 ("PROFIBUS
diagnostics, receive telegram offset PZD") and r2076 ("PROFIBUS diagnostics, send
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 a Publisher of a device (CU) is missing or has failed. Any
interruption to the Publisher is also reported by a fault F01946 at the affected DO. A failure of
the Publisher will therefore only affect the respective DOs.
A description of the two messages can be found in the SINAMICS DCM list manual.
336
SINAMICS DCM Control Module
Operating Instructions, 06.2010, C98130-A7067-A1-02-7619