20
MOVIDRIVE
®
DFC11A CAN Bus
4
Parameter Setting via
CAN Bus
4.1.1.2 Parameter Index Addressing
Byte 2: Index High and byte 3: Index Low are used to identify the parameter to be read or written
via the fieldbus system. The parameters of a drive inverter are addressed using a standard index,
irrespective of the type of fieldbus system. Byte 1 should be considered reserved and must gener-
ally be set at 0x00.
4.1.1.3 Data Area
As shown in Fig. 17, the data are contained in bytes 4 to 7 of the parameter message. This allows a
maximum of 4-byte data to be transferred per service. The data are generally entered flush right,
i.e. byte 7 contains the least significant data byte (data LSB), byte 4 correspondingly the most
significant data byte (data MSB).
MD0232AE
Fig. 17: Definition of the data area in the parameter message
4.1.1.4 Faulty Execution of Service
Faulty execution of service is signalled by setting the status bit in the management byte. If the
status bit indicates an error, the error code is entered in the data area of the parameter message
(Fig. 18). Bytes 4 - 7 provide the return code in a structured format (see MOVILINK
®
Communica-
tions Profile Manual).
MD0233AE
Fig. 18: Structure of the parameter message in the event of faulty execution of service
4.1.2 MOVILINK
®
Parameter Channel
The “MOVILINK
®
Device and Communications Profile” manual provides a detailed description of
the MOVILINK
®
parameter channel.
For the CAN bus system it is important to differentiate between synchronized and non-synchro-
nized parameters.
• In the case of non-synchronized parameter messages, service acknowledgement is independent
of the Sync message.
• In the case of synchronized parameter messages, the service acknowledgement is sent in the
first millisecond after receipt of the Sync message only.
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Management
Reserved
Index High
Index Low
Data MSB
Data
High byte 1
High byte 2
Low byte 1
Low byte 2
High word
Data
Data LSB
Low word
Double word
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Management
Reserved
Index High Index Low
Status bit = 1: Faulty performance of ser vice
Error Class Error Code
Add. Code
high
Add. Code
low
