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Process Data Communication
7.1.3
In Process Data (PDO) communication, a slave exchanges the process data object (PDO) with a master every cycle.
The data to be exchanged is pre-determined by PDO Mapping in the communication initialization state. The PDO
communication of Ezi-IO EtherCAT DA is classified into a Receive PDO (RxPDO) which receives data from the
master and is used when the Ezi-IO EtherCAT DA is in Operational state.
Figure 7-2. EtherCAT PDO Communication
7.2
PDO Mapping
Through the PDO Mapping, sets the application objects to be exchanged through the PDO communication.
PDO Mapping
7.2.1
The mapping information of RxPDO, which receives the master command, is set in Object 1600h. In the mapping
table, it records the object IDs, sub-index values and data length (in bit) of exchanging data.
Figure 7-3. PDO Mapping
PDO Map Object
Object Contents
Index
Sub
Object
Sub
Size
0x1600
1
0x6411
0x01
0x10
0x1600
2
0x6411
0x02
0x10
0x1600
3
0x6411
0x03
0x10
0x1600
4
0x6411
0x04
0x10
Object
Sub
Name
0x6411
0x01
Analogue output CH01
0x6411
0x02
Analogue output CH02
0x6411
0x03
Analogue output CH03
0x6411
0x04
Analogue output CH04
0x0000
0x00
Analogue
output CH01
Analogue
output CH02
Analogue
output CH03
Analogue
output CH04
Application Object List
RxPDO Mapping
RxPDO 0
EtherCAT
Master
Ezi-IO
EtherCAT DA
Rx PDO
Output DATA