Synchronization With Distributed Clocks; Communications Cycle (Dc Cycle); Response Time - Omron OMNUC G5 Series User Manual

5-6 Synchronization with Distributed
Clocks
A mechanism called a distributed clock (DC) is used to synchronize EtherCAT
communications.
The DC mode is used for OMNUC G5-series Servo Drives to perform highly accurate control
in a multi-axis system.
In DC mode, the master and slaves are synchronized by sharing the same clock.
Interruptions (Sync0) are generated in the slaves at precise intervals based on this clock.
Servo Drive control is carried out at this precise timing.

Communications Cycle (DC Cycle)

The communications cycle is determined by setting the Sync0 signal output cycle.
Setting range: 250 µs/500 µs/1 ms/2 ms/4 ms
Precautions for Correct Use
Set 6091 hex (Gear ratio) to 1:1 for 250 µs or 500 µs. If it is not set to 1:1, a Function Setting
Error (Error 93.4) will occur.

Response Time

The following graph shows the response time from the Sync0 signal to when the motor starts.
Master
Network
Servo Drive
Model Command execution time
R88D-KNA5L-ECT-R
R88D-KN01L-ECT-R
R88D-KN01H-ECT-R
R88D-KN02H-ECT-R
R88D-KN02L-ECT-R
R88D-KN04L-ECT-R
R88D-KN04H-ECT-R
OMNUC G5-series AC Servomotors and Servo Drives User's Manual (with Built-in EtherCAT Communications)

5-6 Synchronization with Distributed Clocks

Master
processing
Communications
frame
Sync0
R88D-KN08H-ECT-R
R88D-KN10H-ECT-R
290 to 380 µs
R88D-KN15H-ECT-R
R88D-KN06F-ECT-R
R88D-KN10F-ECT-R
330 to 420 µs
R88D-KN15F-ECT-R
Received
Motor started
Command execution time
Model Command execution time
330 to 420 µs
5
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