Siemens SENTRON VL Series System Manual page 173

Step 3 Set Sync bit
In all affected circuit breakers, set the bit for synchronization of the clocks (bit 7 of byte 1 of
the control byte).
(see Chapter Using cyclic data (Page 155))
Step 4 Sync frame
Send a SYNC command again at the half hour (e.g. 14:30:00). This rounds the clocks up or
down to the half hour in all devices within the SYNC group.
(See Chapter Sync/Unsync/Freeze/Unfreeze (Page 161))
Step 5 Unsync frame
Send an UNSYNC command to the affected SYNC group.
(See Chapter Sync/Unsync/Freeze/Unfreeze (Page 161))
Step 6 Reset Sync bit
In all affected circuit breakers, reset the bit for synchronization of the clocks (bit 7 of byte 1 of
the control byte).
(See Chapter Using cyclic data (Page 155))
3WL/3VL circuit breakers with communication capability - PROFIBUS
System Manual, 03/2011, A5E01051353-02
7.3 Functional sequences/description of functions
Data transfer to the PLC
173