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3.1.3 Process data communication
Process data communication (PDO communication) commands and receives Process Data
Objects (PDO) with master periodically. Data that will be delivered and received is already
defined at the initial stage of communication by PDO Mapping. PDO communication is
categorized as transmission PDO (following Tx PDO) delivers controller status information
and receipt PDO (following Rx PDO) delivers command from the master. This communication
can be used under the operational status of the controller and Tx PDO is only available for
Safe-Operation status.
Figure 3-2: EtherCAT PDO Communication.
3.2
PDO Mapping
PDO Mapping is to set Application Object will be delivered and received by PDO
communication.
3.2.1 PDO Mapping
Tx PDO Mapping information to be delivered to Master is to set at 1600h
∼
1601h Object and
Rx PDO Mapping information to be received command from master is to set at 1A00h
∼
1A01h Object. Object ID value, Low level Index value, length of data (bit unit) of data that will
be delivered and received are recorded at Mapping Table.
Figure 3-3: PDO Mapping.
