ECM NH3CAN, Инструкция по эксплуатации, Страница: 13 / 35

13
6.0 Reading from the NH
3
CAN Module (SDO Read)
During configuration it may be necessary to read certain locations in the Object Dictionary (OD).
The format for a Service Data Object Read (SDO Read) is as follows:
SDO Read Tx
CAN id
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
0x600+NID 0x40 OD lo OD hi Sub
OD lo = low byte of OD address
OD hi = hi byte of OD address
Sub = Subindex of OD address
A SDO Read will generate the following reply:
SDO Read Rx
CAN id
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
0x580+NID Size OD lo OD hi Sub Data0 Data1 Data2 Data3
Size = 0x4F (1 byte response)
0x4B (2 byte response)
0x43 (4 byte response)
OD lo = low byte of OD address
OD hi = hi byte of OD address
Sub = Subindex of OD address
Data0 always contains the Least Significant Byte (LSB) of the data present at the OD address.
Example: Read OD address 0x5008 subindex 0x32 in the module with NID = 0x10
SDO Write Tx
CAN id
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
0x610 0x40 0x08 0x50 0x32
The module will reply as follows:
SDO Write Rx
CAN id
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
0x590 0x4B 0x08 0x50 0x32 0xBC 0x02
OD address 0x5008, subindex 0x32 of the module with NID = 0x10 contains the 2 byte value
0x2BC