8.5.9. CANopen service data objects
Service data objects (SDOs) make it possible to read and write all parameters of the
inverter via CANopen.
Details
Two independent SDO channels are provided at the same time. SDO channel 1 is always
active. SDO channel 2 can be activated via 0x2301:005 (P510.05).
The identifiers for SDO1 and SDO2 are generated from the basic identifier (in compliance
with the "Predefined Connection Set") and the node address set.
An SDO is always transmitted with confirmation, i. e. the reception of an SDO frame is
acknowledged by the receiver.
Structure of the SDO frame user data
The user data are shown in Motorola format:
below.
Address of the parameter to be read or written.
LOW byte
HIGH byte
LOW byte
HIGH byte
The following commands can be transmitted or received for writing and reading the
parameters:
Writing of a parameter to the inverter.
0x2F
47
1 byte
Inverter acknowledges a write request.
Reading of a parameter from the inverter.
Inverter response to a read request with the current parameter value.
0x4B
75
2 bytes
Inverter response to the incorrect execution of the read/write request.
More precisely, the command byte comprises the following information:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Error response
1
0
0
0
0
0
0
0
*Bit coding of the length: 00 = 4 bytes, 01 = 3 bytes, 10 = 2 bytes, 11 = 1 byte
e: expedited (shortened block service)
s: segmented (normal block service)
More commands are defined in the DS301 V4.02 CANopen specification (e.g. segmented
transfer).
To Next Page
Loading...
