Stober SC6 Series Operating Manual

STOBER 9 | Looking for more information about EtherCAT?
02/2020 | ID 443025.06
71
9.5.2.2.2.4 Cycle time < 1ms
For cycle times < 1ms, quality defects can occur in the EtherCAT communication if the receipt of the PDO data from the controller and transmission of the process data from the drive
controller overlap. The following graphic shows unstable synchronization using distributed clocks when using TwinCAT 3.
OI
1
3
2
I
OI
1
3
2
I
OI
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
APPAPP
= Jitter
Cycle time
Fig.18: TwinCAT 3: DC-Sync – Unstable synchronization, cycle time < 1ms
In the example, the data transmission (I/O) of the controller is set to task begin in the EtherCAT configuration. For the application cycle sequence, the order is defined as RxPDO, graphical
programming, TxPDO (A149 = 0).

Stober SC6 Series Specifications

General

Brand	Stober
Model	SC6 Series
Category	Controller
Language	English