Festo Кабели и принадлежности - Manual (Page 64)

5. Data structure
5−6
Festo P.BE−SPC200−COM−CANDN−EN en 0511a
5.2 DeviceNet profiles: I/O assignment and functions
The DeviceNet profile consists of 8 bytes for writing and
8Ăbytes for reading the desired data into/out of the SPC200.
The basic composition of the communication telegram:
Byte 0 1 2 3 4 5 6 7
Command
Message Control
byte Sub−index Command
Message
type Response
Message
type Command Data
Response
Message Status
byte Fault code Response
Message
type Response Data
The Command Message is generated by the user and conĆ
tains commands for writing or reading data. The Response
Message is returned by the SPC200 to the PLC and contains
the data or a fault code if the SPC200 cannot process the
commands.
There are three groups of commands:
Control commands These commands start
ć a program (Start/Stop mode) or
ć an NC record (Record Select mode).
} section 5.2.1
Update commands These commands read
ć the actual positions of the axis or
ć the field bus outputs of the SPC200 (Q10...13).
} section 5.2.2
Parameter commands These commands write or read parameters
(e.g. position register or flag).
} section 5.2.3