Siemens SIMOTION Function Manual page 27

Synchronization in PROFIBUS DP
If the DP slave interface is operated isochronously, the SIMOTION device must be
synchronized with the higher-level bus cycle clock. The synchronization behavior depends on
whether the PROFIBUS DP interfaces of the SIMOTION device have been configured as the
isochronous DP master:
● None of the PROFIBUS DP interfaces have been configured as isochronous DP master
● At least one of the PROFIBUS DP interfaces is configured as isochronous DP master for
Note
A phase jump occurs during synchronization of an isochronous DP master interface with a
higher-level bus cycle clock. This can lead to failures in the connected DP slaves
(e.g. SINAMICS drives).
You should, therefore, deactivate the DP slaves concerned and the technology objects
assigned to them before synchronizing drives that are already in operation. Once
synchronization has been successfully completed, you can reactivate the DP slaves
concerned and their assigned technology objects. See Activating and deactivating
components and technology objects (Page 57).
Note
In SIMOTION D devices, the DP Integrated interface is always configured as the isochronous
DP master interface.
Therefore, if these devices are connected to a higher-level isochronous master, they must
always be synchronized.
Basic Functions for Modular Machines
Function Manual, 04/2014
Synchronizing SIMOTION devices with a higher-level bus cycle clock
3.1 General information about synchronizing a SIMOTION device with the bus cycle clock
for the lower-level drives:
The device is automatically synchronized with the higher-level bus cycle clock.
After successful synchronization, the cycle clocks of the device (e.g. Servo, IPO, IPO2) and
the programs running in the SynchronousTasks are both synchronous with the higher-level
bus cycle clock.
See: Synchronization of a SIMOTION device without isochronous DP master interface
(Page 31).
lower-level drives:
Users must themselves activate synchronization of the device with the higher-level bus
cycle clock using the _synchronizeDpInterfaces system function (user-controlled
synchronization). The user can thereby determine the time of synchronization and take
suitable precautions, such as deactivating affected DP slaves, to avoid system failures
caused by the synchronization process.
Only after successful synchronization are the device cycle clocks (e.g. Servo, IPO, IPO2),
the programs running in SynchronousTasks, and also the isochronous DP master
interfaces all synchronous with the higher-level bus cycle clock.
See: Synchronization of a SIMOTION device with isochronous DP master interface
(Page 33).
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