EtherCAT:EC SDO READ
This function allows reading INTEGER values of sizes 8, 16 and 32 bits.
In order to communicate with a specific slave we use its address and the functions EC_SDO_READ and EC_SDO_WRITE.
To read data from the slave we have to specify a SDO index and a sub-index.
The first sub-index is 0. If only one sub-index exists, we still have to specify 0 (we cannot omit this field).
The read value is returned from the function and can be set to a variable.
Input
Slave address, SDO index, SDO sub-index.
Output
None
Return Value
Value that is read from the slave.
Declaration
public function EC_SDO_READ(byval slaveaddres as long, byval index as long, byval subindex as long) as long
Syntax
retVal = EC_SDO_READ(<Slave address>, <SDO index>, <SDO sub-index>)
Exceptions
EC_SLAVE_ADDRESS_ERROR - "SLAVE ADDRESS ERROR" 20032
EC_SDO_READ_WRITE_ONLY - "SDO READ ERROR: Attempt to read a write-only object" 20060
EC_SDO_READ_SIZE - "SDO READ ERROR: Received an unreasonable amount of data" 20064
Examples
retVal = EC_SDO_READ(2, 0x6041,0) ' Read status word