85
10.3.1 Download (from host to slave)
Download means that the host sends a command to write values to the objects in the slave, the slave
generates an error message if when the value is downloaded to a non-existent object.
The host sends:
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
CMD
INDEX
SUB
INDEX
DATA
CMD:
Specifies the direction of data transfer and the size of data.
23 (hex) Sends 4-byte data (bytes 4...7 contain 32 bits)
2b (hex) Sends 2-byte data (bytes 4 and 5 contain 16 bits)
2f (hex ) Sends 1-byte data (bytes 4 contains 8 bits)
INDEX:
Index in the object dictionary where data should be sent
SUB INDEX:
Sub-index in object dictionary where data should be sent
DATA:
8, 16 or 32 bit value
The slave answers:
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
RES
INDEX
SUB
INDEX
RESERVED
RES:
Displays slave response:
60(hex) Data successfully sent
80(hex) Error, bytes 4…7 contain error cause
INDEX:
16-bit value, copy of index in host telegram
SUBINDEX:
8-bit value, copy of sub index in host telegram
RESERVED:
Not used
10.3.2 Upload (from slave to host)
Upload means the master sends a command to read the object value from the slave. The slave
generates an error if a non-existent object is requested.
The master sends:
byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7
CMD
INDEX
SUB
INDEX
RESERVED
CMD:
Specifies the direction of data transfer
40(hex) always
INDEX:
16-bit value, index in the object dictionary where requested data reside.
SUBINDEX:
8-bit value, index, sub index in the object dictionary where requested data reside.
RESERVED:
Bytes 4…7 not used
