Siemens SIMOTION Function Manual page 30

Synchronizing SIMOTION devices with a higher-level bus cycle clock
3.1 General information about synchronizing a SIMOTION device with the bus cycle clock
depends on whether the PROFIBUS DP interfaces of the SIMOTION device have been
configured as 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.
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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 Synchronizing a SIMOTION device without an isochronous DP master interface
(Page 31).
lower-level drives:
Synchronization of the device and the isochronous DP master interfaces is different:
– The device (not including the DP master interfaces) 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.
– Synchronization of the isochronous DP master interfaces with the higher-level bus cycle
clock must be activated by the users using the _synchronizeDpInterfaces system
function. 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 has been completed are the isochronous DP
master interfaces synchronous with the higher-level bus cycle clock.
See Synchronizing a SIMOTION device with an isochronous DP master interface
(Page 33).
Basic Functions for Modular Machines
Function Manual, 04/2014