PN/CAN Gateway, PROFINET/CANopen Slave | Version 2 | 1/26/2021
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7.3
Read/write random SDO
With the pluggable modules for reading and writing SDOs a cyclic I/O access to the SDO data with a
size of up to 4 bytes can be performed. In case SDOs with more than 4 bytes of data are to be read or
written or SDOs are to be accessed only rarely, the module "read/write any SDO" can be used.
With this module an SDO can be accessed randomly on a command based exchanged.
Control SDO transfer (9 bytes outputs):
Byte/Bit
7
6
5
4
3
2
1
0
Out 0
1 = Enable
SDO transfer
-
Length for SDO write:
0 = 1 Byte … 3 = 4 Bytes
1= swap
byte order
0 = read SDO
1 = write SDO
1 = start
transfer
1 = Freeze
Out 1
SDO-Index
Out 2
Out 3
SDO-Subindex
Out 4
Byte offset for SDOs with length > 4 bytes
Out 5
Data
Out 6
Out 7
Out 8
Status of SDO transfer (9 bytes inputs):
Byte/Bit
7
6
5
4
3
2
1
0
In 0
1 = SDO
transfer
enabled
1 = SDO
error
Read length for SDO:
0 = 1 Byte … 3 = 4 Bytes
Mirror of
“swap
byte order”
0 = read SDO
1 = write SDO
1 = transfer
running
1 = Freezed
In 1
SDO Data
In 2
In 3
In 4
In 5
SDO Abort code
In 6
In 7
In 8
As long as the freeze – bit is set, the access from the CAN bus of the corresponding SDO is blocked.
