LS ELECTRIC L7NHF Series, User Manual

Page: 68 / 409

3. EtherCAT Communication
3-8
3.5
Synchronization Using the DC
(Distributed Clock)
The Distributed Clock (DC) synchronizes EtherCAT communication. The master and slave share a
reference clock (system time) for synchronization, and the slave synchronizes its applications with the
Sync0 event generated by the reference clock. The following synchronization modes exist in this drive.
You can change the mode with the sync control register.
(1) Free-run Mode:
In Free-run mode, it operates each cycle independent of the communication cycle and master cycle.
(2) DC Synchronous Mode:
In DC Synchronous mode, the Sync0 event from the EtherCAT master synchronizes the drive. Please
use this mode for more precise synchronous control.
3.6
Emergency Messages
Emergency messages are passed to the master via mailbox communication when a servo alarm
occurs in the drive. Emergency messages may not be sent in the event of communication failure.
Emergency messages consist of 8-byte data.
Byte 0 1 2 3 4 5 6 7
Details
Emergency
Error Code
(0xFF00)
Error Register
(0x1001)
Reserved
Unique Field for Each Manufacturer
Servo Alarm
Code
Reserved
Master Application
Master
Slave
Master Application
Frame U U
U U
Frame U
U
Sync0
Event
Sync0
Event
Sync0
Event
Cycle time (0x1C32:02) Cycle time (0x1C32:02)
Master user
shift time
Sync0 shift time
Shift time (0x1C33:03)
Calc + Copy time
(0x1C33:06)
Shift time (0x1C32:03)
Calc + Copy time
(0x1C32:06)
Inputs Latch
Outputs Latch