Motion iWMC Series User Manual

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7.2.1 CANOpen bus communicaon soware
EDS Introducon
EDS (Electronic Data Sheet) le is an idencaon documents or similar code of slave device, to idenfy what kind of
slave device is (Like 401, 402 and 403, or which device type of 402) .This le includes all informaon of slaves, such as
manufacturer, sequence No., soware version, supportable baudrate, mappable OD and aributes of each OD and so on,
similar to the GSD le for Probus. Therefore, we need to import the EDS le of slave into the soware of master before
we congure the hardware.
SDO Introducon
SDO is mainly used in the transmit the low priority object between the devices, typically used to congure and manage
the device, such as modifying PID parameters in current loop, velocity loop and posion loop, and PDO conguraon
parameters and so on. This data transmission mode is the same as Modbus, that is it needs response from slave when
master sends data to slave. This communicaon mode is suitable for parameters seng, but not for data transmission
frequently.
SDO includes upload and download. The host can use special SDO instrucons to read and write the OD of servo. In
CANOpen protocol, SDO (Service Data Object) can be used to modify object diconary. SDO structure and guidelines
are shown below:
SDO basic structure is: Client→ Server/Server→ Client
Byte0CAN
frame
data byte
Byte1-2
Byte3
Byte4-7
length, trigger bit for alternate
zeroing and asseron of each
subsequent segment (toggle bit)
SDO Command specier
Object index
Object subindex
Max 4 bytes data
The SDO command word contains the following informaon:
⚫ Download/upload
⚫ Request/response
⚫ Segmented/expedited transfer
⚫ CAN frame data byte length, trigger bit for alternang zeroing and asserng of each subsequent segment (toggle
bit)
Five request/reply protocols are implemented in SDO:
⚫ Iniate Domain Download
⚫ Download Domain Segment
⚫ Iniate Domain Upload
⚫ Upload Domain Segment
⚫ Abort Domain Transfer.
Among them, Download refers to the write operaon of the object diconary, and upload refers to the reading
operaon of the object diconary; When reading parameters, use the Iniate Domain Upload protocol; When seng
parameters, use the Iniate Domain Download protocol; The SDO command word (rst byte of the SDO CAN message)
syntax of the protocol is described in Tables 10-8 and 10-9, where "-" indicates irrelevance and should be 0) .

Motion iWMC Series Specifications

General

Brand	Motion
Model	iWMC Series
Category	Industrial Equipment
Language	English