SV-iS7 CANopen Manual
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4.1.2 SDO
communication
Regardless of the connection of the CANopen with the master, this is the protocol for the client to read or write
data on the server.
SDO Download means the client writing data on the server, and the SDO Upload is the client reading data from
the server.
4.1.3 PDO
communication
According to the protocol, the only the Index and SubIndex Data which are specified to the PDO are transmitted.
Though the data type of the PDO can be set up by mapping, the IS7 prohibits setting by mapping.
PDO has two types which are Transmit-PDO (TPDO) and Receive-PDO (RPDO).
PDO is classified into the Producer and Consumer, which are different from the server and client in the SDO
communication. The Producer can be a client or a server. The Producer of the TPDO is a server and the
Producer of the RPDO is a client. This is because the PDO is classified in the perspective of the server. The
Consumer is the recipient of the PDO created by Producer.
4.1.3.1 Transmission
modes
Synchronous transmission: PDO is transmitted according to SYNC frame
Event-driven transmission: PDO is transmitted by an event.
4.1.3.2 Triggering
modes
There are 3 trigger modes available for the generation of the event for PDO transmission.
z
Event- and timer-driven
When the preset event time is elapsed the PDO frame is transmitted automatically.
z
Remotely requested
PDO frame is transmitted when the RTR frame requesting for PDO is received.
z
Synchronously triggered
PDO frame is transmitted by the preset number of the SYNC frames.