Siemens MICROMASTER 420 Operating Instructions Manual page 43

Issue 01/05
Example 2: Writing into parameter P1203
In order to write the value 99 (decimal) into parameter P1203.00, the parameter
number must first be converted into a hexadecimal number:
1203dec = 4B3H
Then, 2000H must be added:
04B3H + 2000H = 24B3H
The numerical sequence after the point in the specification of the PKW object (in
this case: 0 in P1203.00) corresponds to the subindex number of the CANopen
object. It must be converted from a decimal number into a hexadecimal number:
00 dec =0H
The data type of the parameter must now be taken from the MICROMASTER
parameter list. This is for parameter P1203 unsigned 16 (U16).
The value to be written (in this case, 99 decimal) must be specified in the CANopen
telegram as hexadecimal number:
99dec = 63H
Now, an SDO write request is defined for the object that was determined:
• Byte 0
− Bit 5 - 7 (CCS)
− Bit 4
− Bit 2 - 3
− Bit 1
− Bit 0
• Byte 1
− Bit 0 - 7
• Byte 2
− Bit 0 - 7
• Byte 3
− Bit 0 - 7
• Byte 4-5
− Bit 0 - 7
• Byte 6-7
− Bit 0 - 7
CANopen telegram of the master
Table 3-9 SDO write request for parameter (object 0x24B3* sub0)
Byte 0:
Bits 7-5 Bit 4 = 0 Bits 3,2
CCS = 1 n = 2 (Word)
CANopen Option Module Operating Instructions
6SE6400-5BC00-0BP0
= 1H ->initiate download request
= 0H ->always for initiate download request
= 2H ->n=number of bytes that do not contain any data
= 1H ->e=1 expedited transfer
= 1H ->s=1 data size is indicated
= B3H ->index of the object, part 2
= 24H ->index of the object, part 1
= 00H ->subindex of the object
= 63H ->data that is to be written into
= 00H ->data that is to be written into, in this case empty
Bytes 1,2
e = 1 s = 1 24B3H
Data transfer using CANopen
Byte 3 Bytes 4,5
0H 63H
Bytes 6,7
0H
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