Process Data Objects (Pdos) - Omron SYSMAC FH Series User Manual

2 Methods for Connecting and Communicating with External Devices
2-1-5

Process Data Objects (PDOs)

This section describes the process data objects (PDO) used in EtherCAT communications.
Introduction
Real-time data transfer in cyclic communication uses Process Data Objects (PDOs).
There are two types of Process Data Objects (PDOs): RxPDOs, which are used by the EtherCAT
slave terminal to receive data from the EtherCAT master; and TxPDOs, which are used by the Ether-
CAT slave terminal to send data to the EtherCAT master.
EtherCAT master
Example: Built-in
EtherCAT port
on NJ-series
CPU Unit
The EtherCAT application layer can hold more than one object to enable the transfer of various proc-
ess data of the EtherCAT slave terminal.
The contents of the process data is defined in the PDO mapping objects.
EtherCAT slave terminals support PDO mapping for I/O control.
2 - 10
RxPDO
Output data and motion
commands to NX Units
(Output Units)
TxPDO
Status of EtherCAT Slave
Terminals and input data
from NX Units (Input Units)
FH/FHV Series Vision System User's manual for Communication Settings (Z342-E1)
EtherCAT
Slave
Terminal