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Functions
4.6.4
SDO
A Service Data Object (SDO) provides a direct access to the object entries of a CANopen€ device's
Object Dictionary. These object entries may contain data of any size and data type. SDO is used to
transfer multiple data sets from a client to a server and vice versa. The client controls which data set
is to be transferred via a multiplexer (index and sub-index of the Object Dictionary). By using the Com-
mand Interface (CIF), it is possible to make an SDO access to other CANopen€ devices or to the
ME3CAN1-L itself. No configuration is needed in the Object Dictionary.
For details of the Command Interface, please refer to chapter 5.
Fig. 4-3:
4.6.5
RPDO / TPDO
Real-time data transfer is performed by the Process Data Objects (PDO). The transfer is performed
with no protocol overhead.
PDOs correspond to objects in the Object Dictionary and provide the interface to the application
objects. Data type and mapping of application objects into a PDO is determined by a corresponding
default PDO mapping structure within the Object Dictionary. The variable mapping of PDO and the
mapping of application objects into a PDO may be transmitted to a CANopen€ device during the con-
figuration process by applying the SDO services to the corresponding objects of the Object
Dictionary.
The PDO communication parameter describes the communication capabilities of the PDO.
The PDO mapping parameter contains information about the contents of the PDO.
PDO producer
Fig. 4-4:
4 – 20
Client
Request
Confirmation
Data transfer using SDOs
Request
Request
Process data: L bytes of application data
Transfer of PDOs
Process data
0 < L 8
Communication Profile Area
Server
Indication
Response
PDO consumers
Indication
Indication
Indication
MITSUBISHI ELECTRIC
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