Service Data Object (Sdo); Sdo Protocol And Message Format - Econ EtherCAT EHS-580 User Manual

SHENZHEN ECON TECHNOLOGY CO.,LTD
Items
Fieldbus
Message structure
SDO data collection
PDO data collection
The length for Each PDO mapping
Communication state machine
Identification of communication
objects

5.3.1 Service data object (SDO)

EHS-580 hybrid servo drive supports SDO function, the EtherCAT master can write/read the object dictionary of
drive ,and configure ,monitor, control the drive by SDO.
The SDO is the user/server mode, the master is corresponds to the user in the SDO operation, and
The drive is a server, all of transmission/command must be from master to user.
At the CANopen DS301 mode, the SDO protocol can transmit 8 bytes one time in order to match the
data length of CAN packets. at the COE enhancement mode, it expand the payload data only, and don't change the
protocol header. In this way, the SDO can use the larger mailbox, and improve the efficiency of data transmission.

5.3.2 SDO protocol and message format

Here are two SDO service supported by EHS-580 hybrid servo drive
A:Fast transmission service: it is same as CANopen DS301,use 8 bytes only to transmit 4 bytes of valid data
B:Conventional transmission service: the max bytes of transmission data depend on the capacity of mail box
manager.
SDO download service format as below chart
The details table for transmission requested service data of SDO downloading
User Manual For EHS-580 EtherCAT Hybrid Servo Drive
COE
EtherCAT
Standard Ethernet
SM mailbox data area
SM processing data area
Maximum 32 bytes
0x120/0x130 register
Synchronization management
(SM)
DS301
CAN
CAN 2.0Astandard
CAN message
CAN message
Maximum 8bytes
NMT (network management tool)
COB-ID (object dictionary identification
code)