The NMT Master Startup process uses SDOs. An error may be returned by the CIF (command interface)
if during command execution the NMT Master accesses the remote node at the same time.
CIF SDO read access
Execution procedure: CIF SDO read access
● Write the command code 0004
● Write the Node number and the Index / Sub-index of the target Object Dictionary to Un\G1001
● After writing all the necessary parameters turn ON Y(n+1)7 in order to trigger the command
execution. If the command execution is finished, X(n+1)7 will be turned ON.
● If the access has been successful, Un\G1000 will contain "5" and Un\G1001 to Un\G1003 will
contain the node number, index and sub index for verification purposes. The length of the read
data (in byte) will be stored in Un\G1004. Un\G1005 to Un\G1066 will contain up to 124 data bytes.
Buffer memory allocation
Node number 0 is accessing the local ME3CAN1-L modules Object Dictionary, regardless of its real node address. This is
useful as the configuration of the local node can be programmed independently from the node address.
Result data structure in Un\G1005 to Un\G1066
5 – 2
: SDO read
Low byte: Sub index
High byte: Reserved
Buffer memory allocation for CIF SDO read access
2nd data byte
1st data byte
4th data byte
3rd data byte
6th data byte
5th data byte
8th data byte
7th data byte
122nd data byte
121st data byte
124th data byte
123rd data byte
for SDO read access to Un\G1000.
Index (read back)
Sub index (read back)
Data length (read back)
Result data structure
: SDO read success
: Error (Refer to section 5.4)
: CIF Busy