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Communication Function
Chapter 7.
7.1
CAN Application Protocol Over EtherCAT
Ezi-IO EtherCAT AD is an analog input module that supports CAN application protocol over EtherCAT (CoE). Ezi-
IO EtherCAT AD has the following communication structure.
Figure 7-1. Communication Structure of Ezi-IO EtherCAT AD
Object Dictionary
7.1.1
The Object Dictionary is the group of data objects which are saved in an EtherCAT slave unit. EtherCAT masters
can read and write data through the index or sub-index of objects.
Mailbox Communication
7.1.2
In the Mailbox (SDO) communication, a master and a slave exchange the service data object (SDO). It is a
message transmission and reception method. If the master sends a command, the slave Ezi-IO EtherCAT AD
answers to it.
The SDO communication is used for setting or checking objects in the Object Dictionary when the Ezi-IO
EtherCAT AD is in Pre-Operational, Safe-Operational, or Operational status.
