Siemens MICROMASTER 430 - Page 39

Issue 01/05 Data transfer using CANopen
CANopen Option Module Operating Instructions
6SE6400-5BC00-0BP0
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In order to read objects from the MICROMASTER 420/430/440, a CANopen
master must send an SDO upload protocol according to the following table.
Table 3-5 Significance of the bytes in the SDO upload protocol (CANopen master to MICROMASTER)
Byte 0: Control Word Bytes 1,2 Byte 3 Bytes 4,5 Bytes 6,7
Bits 7-5
CCS = 2
Bit 4 - 0 = 0 Object
Dictionary
Index
Object
Dictionary
Subindex
Reserved = 0
If the MICROMASTER 420/430/440 cannot correctly process the task, it
acknowledges the upload SDO protocol using a response telegram according to
the following table:
Table 3-6 Significance of the bytes in the SDO upload protocol (MICROMASTER to CANopen master)
Byte 0: Bytes 1,2 Byte 3 Bytes 4,5 Bytes 6,7
Bits 7-5
SCS = 2
Bit 4 = 0 Bits 3,2
n = 0 (Dword)
n = 2 (Word)
e = 1 s = 1 Object
Dictionary
Index
Object
Dictionary
Subindex
Word data
Dword data Dword data
Abort SDO transfer protocol
SDO tasks, which the MICROMASTER 420/430/440 cannot process are
responded to using an abort SDO protocol. If the MICROMASTER does not
respond in the expected time, the CANopen master sends an abort SDO protocol.
0 1 2 3 4 7
CLIENT/SERVER SERVER/CLIENT
Request
Indication
7 ... 5
cs = 4
4 ... 0
x
Index
Sub-
index
Abortcode
Fig. 3-9 Abort SDO transfer protocol
In this case, there are various abort codes. The abort codes, which occur in the
MICROMASTER 420/430/440, are listed in the following table. Most of the faults
occur due to communication errors between the CANopen option module and
MICROMASTER. In order to be able to access the parameters in the
MICROMASTER, SDO tasks must be re-coded into parameter tasks and then sent
to the MICROMASTER via the SOL. If the MICROMASTER cannot correctly
process the parameter task which it was issued, then it signals this in the form of a
response to the option module. In turn, the option module transforms this response
into the abort codes listed in the table. If the MICROMASTER sends an abort code,
the parameter request issued must be re-checked and repeated.