Siko AG06 - 9.3.7 Service Data Objects (SDOs)

Communication via CAN bus
AG06 Date: 07.02.2018 Art. No. 85674 Mod. status 055/18 Page 43 of 114
Asynchronous:
Sub-index 2 (transfer type) = 254 ... 255
In the asynchronous transfer type, the Receive PDOs are processed by the actuator
immediately after receipt of the Receive PDO.
9.3.7 Service Data Objects (SDOs)
Service Data Objects (SDOs) serve in the first place for transferring device configuration
parameters.
8 bytes of user data are always transferred in a SDO. The identifier is set to 11 bits and cannot
be changed.
The exchange of SDOs is enabled in the NMT statuses "Pre-Operational" as
well as "Operational"!
There is each one COB ID for data transfer from the master to the actuator (COB-ID 600
h
+
Node-ID) and one COB ID for data transfer from the actuator to the master (COB-ID 580
h
+
Node-ID).
Data transfer is always initiated and controlled by the master.
The COB IDs for the Service Data Objects cannot be changed.
SDO Telegram
11 Bit
Identifier
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Command
Parameter index
Sub-index
Data 1
Data 2
Data 3
Data 4
Table 23: Setup of the SDO telegram
Byte 1: Command code
The first byte contains the command code of the SDO telegram. The following table lists the
available commands and describes their meaning.
Command
Command code
hexadecimal
Command
code decimal
Meaning
Write Request
23
h
35
send parameters (4 data byte)
Write Request
2B
h
43
send parameters (2 data byte)
Write Request
2F
h
47
send parameters (1 data byte)
Write Response
60
h
96
response of Write Request
Read Request
40
h
64
request of a parameter
Read Response
43
h
67
response to the request (4 data byte)
Read Response
4B
h
75
response to the request (2 data byte)
Read Response
4F
h
79
response to the request (1 data byte)
Error Response
80
h
128
error message
Table 24: Command codes