Service Data Objects (Sdo) - ABB FCAN-01 User Manual

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Service Data Objects (SDO)

Service Data Objects are mainly used for transferring non-time
critical data, for example, parameter values. SDOs provide access
to the entries in the device Object Dictionary.
If 4 bytes (or less) of data is to be transmitted, an Expedited
transfer SDO message can be used. Larger quantities of data can
be segmented, that is, split between several CAN messages.
The following services can be applied to SDO depending on the
service requirements:
• SDO Upload, which can be divided into
- Initiate SDO Upload
- Upload SDO Segment.
• SDO Download, which can be divided into
- Initiate SDO Download
- Download SDO Segment.
• Abort SDO Transfer
With expedited transfer all data is transferred during the
initialisation phase (Initiate SDO Upload/Download). With
segmented transfer only part of the data is transferred during the
initialisation phase and the rest of the data is transferred during
the Upload/Download SDO Segment phase.
The COB IDs for the SDO communication are:
• Client to Server (Master to Slave): 600h + Node ID
• Server to Client (Slave to Master): 580h + Node ID.
Communication