Transmitting parameter data
Telegram structure
8
Networking via system bus (CAN)
8.4
8.4.1
L
8.4−1
EDSPM−TXXX−9.0−11/2009
8.4 Transmitting parameter data
Parameter data are the so−called indices.
Parameters are usually set only once during commissioning.
Parameter data are transmitted as so−called SDOs (Service Data Objects) via the
system bus and acknowledged by the receiver, i.e. the transmitter gets a feedback
if the transmission was successful.
8.4.1 Telegram structure
Structure of the telegram for parameter data:
11 bits 8 bytes of user data
Identifier
Instruction
code
Index
Subindex Data 1 Data 2 Data 3 Data 4
LOW byte HIGH byte
l The subchapters below explain the individual telegram components in detail.
l Chapter 8.4.2 contains an example of how to write a parameter. ( 8.4−4)
l
Chapter 8.4.3 contains an example of how to read a parameter. ( 8.4−5)
Identifier
Instruction
code
Index
Subindex Data 1 Data 2 Data 3 Data 4
LOW byte HIGH byte
Two parameter channels are available for parameter data transmission. They are
addressed via the identifier.
Identifier =
Basic identifier
+ node address of the device
dec hex
SDOs
Parameter channel 1
Output (transmit) 1408 580
+ value set with coding switch
Input (receive) 1536 600
Parameter channel 2
Output (transmit) 1472 5C0
+ value set with coding switch
Input (receive) 1600 640
) Note!
There is an offset of 64 between the identifiers for parameter
channels 1 and 2:
l Output of parameter channel 1 = 1536
l Output of parameter channel 2 = 1536 + 64 = 1600
Identifier