Ethercat State Machine (Esm); Communication State - Mitsubishi Electric MELSERVO MR-JET-G-N1 User Manual

2.2

EtherCAT State Machine (ESM)

The communication states of the MR-JET-_G-N1 servo amplifier are classified and managed by EtherCAT State Machine
(ESM) which is defined in the EtherCAT standard.

Communication state

Communication states are classified as shown in the table below. There are two types of communication: PDO
communication (process data object) in which command data and feedback data are transmitted and received cyclically, and
SDO communication (service data object) in which object data is transmitted and received asynchronously.
Page 14 PDO (Process Data Object) COMMUNICATION
Page 19 SDO (Service Data Object) COMMUNICATION
ESM state
Init
Pre-Operational
Safe-Operational
Operational
Bootstrap
2 EtherCAT COMMUNICATION
10
2.2 EtherCAT State Machine (ESM)
Description
The ESM state after turning on the power is the Init state. No SDO communication or PDO communication is possible. The master
station accesses the DL-Information registers and initializes the communication.
SDO communication is possible. PDO communication is not possible. Initial network settings are configured and the initial transfer
of parameters are made in this state.
SDO communication is possible. PDO communication is also possible, although all the operations (commands) such as driving
servo motors are disabled. When the DC mode is selected, synchronization is established in this state.
Both the SDO communication and the PDO communication are possible. Commanding via PDO communication is enabled, and
servo motors can be driven.
Mailbox communication via the FoE protocol is possible. This is a state in which the firmware is updated via EtherCAT. (For
manufacturer setting)