This document describes the procedures for connecting 3G3MX2 Series Type V1 Multi-function Compact Inverter of OMRON to NJ/NX-series Machine Automation Controller via EtherCAT and the procedures for checking their connections.
Refer to Section 6. EtherCAT Settings and Section 7. EtherCAT Connection Procedure to understand the setting method and key points to operate PDO Communications via EtherCAT. In this document, the operations for PDO communications via EtherCAT are checked by the output frequency setting and the status check of Inverter.
PDO communications
This method is used for cyclic data exchange between a master unit and slave units.
PDO data (i.e., I/O data that is mapped to PDOs) that is allocated in advance is refreshed periodically each EtherCAT process data communications cycle (i.e., the period of primary periodic task).
The NJ-series Machine Automation Controller uses the PDO communications for commands to refresh I/O data in a fixed control period, including I/O data for slaves, and the position control data for servomotors.
It is accessed from NJ-series Machine Automation Controller in the following ways.
・With device variables for a slave I/O
・With axis variables for a servo drive and an encoder input slave to which assigned as an axis
SDO Communications
This method is used to read and write the specified slave unit data from a master unit when required.
The NJ-series Machine Automation Controller uses SDO communications for commands to read and write data, such as for parameter transfers, at specified times.
The NJ-series Machine Automation Controller can read/write the specified slave data (parameters and error information, etc.) with the EC_CoESDORead (Read CoE SDO) instruction or the EC_CoESDOWrite (Write CoE SDO) instruction.