84
byte 0
byte 1 …byte 8
byte 9
ID
data
CHKS
ID: The ID number of the slave
CHKS: Telegram checksum, CHKS = SUM(byte 0 …. byte 8)
10.2.1 Point to point protocol
One host communicates with one controller, RS232_Loop_Enable(d5.15)=0)
The host sends:
byte 0
byte 1 …byte 8
byte 9
ID
host data
CHKS
The slave sends / The host receives
byte 0
byte 1 …byte 8
byte 9
ID
slave data
CHKS
If the slave finds it’s own ID in the host telegram, it checks the CHKS value. If the checksum does not match
the slave would not generate an answer and the host telegram would be discarded.
10.2.2 Multi-point protocol
One host communicates with several controllers, RS232_Loop_Enable(d5.15)=1
The host sends:
byte 0
byte 1 … byte 8
byte 9
ID
host data
CHKS
The slave sends / The host receives (RS232_Loop_Enable(d5.15)=1):
byte 0
byte 1 … byte 8
byte 9
byte 0
byte 1 … byte 8
byte 9
ID
host data
CHKS
ID
slave data
CHKS
If the host sends a telegram with an unused ID data will pass the RS232 loop but no slave answer will return.
The slave which finds it’s own ID in the host telegram checks the CHKS value. If the checksum does not
match the slave would not generate an answer and the host telegram would be discarded by that slave.
10.3 Data protocol
The data content of the transport protocol is the data protocol. It contains 8 bytes. The definition of the
CMMB motor controller’s RS232 data protocol is compatible with the CANopen SDO protocol, as well as the
internal data organisation complies to the CANopen standard. All parameters, values and functions are
accessible via a 24-bit address, built of a 16-bit index and 8-bit sub-index.
