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02/2020 | ID 443025.06
Changing the cycle sequence
For cycle times < 1 ms, change the cycle sequence of the application to RxPDO, TxPDO, graphical programming (A149 = 1). The following example shows a synchronization with a changed
cycle sequence. The frame jitter (controller) and application jitter (drive controller) are separated and synchronization is stable.
O
I
1
3
2
I
O
I
1
3
2
I
O
I
1
2
O
O
Beckhoff CX2030
Frame
SYNC Shift Time
Shift Time User Defined
Data ready
SYNC 0
PLL phase offset
AR1
Cycle time
Cycle time
NC+PLC
NC+PLC
NC+PLC
APP
APP
= Jitter
Cycle time
Fig. 19: TwinCAT 3: DC-Sync – Stable synchronization, cycle time < 1 ms