Omron NX102 series

3 EtherCAT Communications
3-6
NJ/NX-series CPU Unit Built-in EtherCAT Port User’s Manual (W505)
SDO communications are used to read and write specified slave data from the master when required.
This is called SDO communications.
You can read/write the following specified slave data with the EC_CoESDORead (Read CoE SDO)
instruction or the EC_CoESDOWrite (Write CoE SDO) instruction.
• SDO data in slaves (parameters, error information, etc.)
There are three types of EtherCAT variables as listed below.
SDO Communications
3-1-3 Types of EtherCAT Variables
Variable type Description
Allocated
variables
Device variables These are common in-out variables for EtherCAT slaves. You can change
the names of these variables.
EtherCAT
Slave configuration
EtherCAT
slave
EtherCAT
slave
EtherCAT
slave
Special Unit Special Unit Basic I/O Unit Basic I/O Unit EtherCAT master
CPU Unit
Device variables for I/O
ports