Function Description
The READ_SDO function block reads
(explicit exchange) from the PLC application up to the device (SDO).
This function block provides access to the abort code when the SDO command is not successful (only if the fieldbus is in RUN mode, and only towards the configured devices).
FBD Representation
Representation:
LD Representation
IL Representation
Representation:
CAL READ_SDO_Instance (ENABLE := EnableREAD_SDO,
ABORT := AbortREAD_SDO, ADDR := DataStructureAddress, NODE := NodeNumber,
INDEX := SDOIndex, SUBINDEX := SDOSubIndex, OFFSET := FirstSDO, NB_IN
:= DataNumberIn, DONE => ReadSDOSuccessful, ACTIVE => ReadSDOActive,
ERROR => ReadSDOFaulty, STATUS => ErrorCode, SDOABORTCODE => AbortCode,
NB_OUT => DataNumberOut, DATA => SDODataToRead)
ST Representation
Representation:
READ_SDO_Instance (ENABLE := EnableREAD_SDO,
ABORT := AbortREAD_SDO, ADDR := DataStructureAddress, NODE := NodeNumber,
INDEX := SDOIndex, SUBINDEX := SDOSubIndex, OFFSET := FirstSDO, NB_IN
:= DataNumberIn, DONE => ReadSDOSuccessful, ACTIVE => ReadSDOActive,
ERROR => ReadSDOFaulty, STATUS => ErrorCode, SDOABORTCODE => AbortCode,
NB_OUT => DataNumberOut, DATA => SDODataToRead)
Parameter Description
The following table describes the input parameters:
Input parameter |
Data type |
Description |
|---|---|---|
ENABLE |
BOOL |
ON: the operation is enabled. |
ABORT |
BOOL |
ON: the currently active operation is aborted. |
ADDR |
ANY_ARRAY_INT |
Array containing the address of the destination entity of the read operation, result of ADDMX function. |
NODE |
BYTE |
Byte used to select a particular NMT slave device on the CANopen network (16#01 to 16#7F). |
INDEX |
INT |
Two bytes used to access a particular object in a CANopen SDO server device. |
SUBINDEX |
BYTE |
Byte used to access a particular subobject in a CANopen SDO server device. |
OFFSET |
INT |
Two bytes indicating the starting offset into the selected object. It can be non-zero when performing segmented SDO transfers. NOTE: Not used when addressing
an EtherNet/IP module (address with CIP suffix).
|
NB_IN |
INT |
Two bytes providing a count of the desired number of data values to read (in bytes). NOTE:
|
The following table describes the output parameters:
Output parameter |
Data type |
Description |
|---|---|---|
DONE |
BOOL |
ON: the operation concludes successfully. |
ACTIVE |
BOOL |
ON: the operation is active. |
ERROR |
BOOL |
ON: the operation is aborted without success. |
STATUS |
WORD |
Provides the error code if an error is detected by the function block. |
SDOABORTCODE |
DWORD |
SDO abort code when |
NB_OUT |
INT |
Size of data (in BYTES) actually returned in the output parameter DATA. |
DATA |
ANY_ARRAY_BYTE |
Read data. |