West Control Solutions KS 800 CANopen Interface Manual - Manual (Page 7)

KS 800 CAN-Interface
2 Service data objects
An SDO is logically determined to exactly two partners - 1 master and 1 slave. Simultaneous
access to the KS800 by two different masters is not possible, since only one SDO channel is
available for "tx" and for "rx".
Max. 4 bytes of usable data can be transmitted by means of SDOs. The remaining 4 bytes are
used as follows:
1 byte for the command: transmission mode
2 bytes for the index: object identification
(e.g. 0x2213 for Wvol - see object directory)
1 byte for the subindex: channel number
An example of an SDO data frame for reading and for writing is given below.
Example 1. A master sends a set-point to a KS800 with node address 4:
The message structure is as follows:
⇒
COB_ID = SDO at node 4 = 0x600 + 4 = 0x604
⇒
CMD = write access = 0x2B = 0x2B
⇒
INDEX = set-point = 0x2213 = 0x2213
⇒
SUBINDEX = e.g. controller 1 = 01 = 0x01
⇒
WERT = 30,0
°
C * ) = 300 * ) = 0x12C
* ) Fixedpoint1: 1 fixed digit behind the decimal point.
8 data bytes
COB-ID LEN Cmd Index Sub. Data
Enquiry:
(Master)
0x604 0x08 0x2B 0x13
0x22 0x01 0x2C 0x02 0x00 0x00
Reply:
(KS800)
0x584 0x08 0x60 0x13
0x22 0x01 0x00 0x00 0x00 0x00
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