Profichip VPC3+C - Page 65

PROFIBUS DP Extensions 7
Data_Ex SYNCH SYNCH
Data_Ex
GC SYNCH
telegrams
SYNC
DX_Out*
New_GC_Command*
SYNC
DX_Out*
New_GC_Command*
IsoM
Simple Sync Mode
Figure 7-17: SYNC-signal and interrupts for synchronization modes (picture only
shows the effects by reception of telegrams; time between telegrams is not equal)
Isochron Mode
To enable the Isochron Mode in the VPC3+C, bit SYNC_Ena in Mode
Register 2 must be set. Additionally the Spec_Clear_Mode in Mode
Register 0 must be set. The polarity of the SYNC signal can be adjusted
with the SYNC_Pol bit. The register Sync_PW contains a multiplicator with
the base of 1/12 µs to adjust the SYNC pulse width. Settings in the
Set_Prm telegram are shown below.
The Structured_Prm_Data block IsoM (Structure_Type = 4) is also
required for the application. If it is sent by Set_Prm telegram the bit
Prm_Structure must be set.
VPC3+C User Manual
Revision 1.03 65
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