3 Basics

IL•1F CANopen DS301

3.3.4Reading and writing data

Writing data The client starts a write request by sending index, subindex, data length and value.

The server sends a confirmation indicating whether the data was cor- rectly processed. The confirmation contains the same index and subindex, but no data.

Client

 

 

 

 

 

 

 

 

 

Server

write request

 

 

0

1

2

3

4

5

6

7

 

 

 

 

COB-ID

 

ccd

Idx2 Idx1 Sidx

 

data

 

 

 

ccd= 23h

 

 

 

 

data

 

 

 

ccd= 27h

 

 

 

data

 

 

 

ccd= 2Bh

 

 

 

data

 

 

 

ccd= 2Fh

 

 

 

data

 

 

 

 

0

1

2

3

4

5

6

7

 

write response

 

 

 

COB-ID

ccd Idx2 Idx1 Sidx

 

data

 

 

 

ccd= 60h

 

 

 

 

 

 

 

 

 

Figure 3.13 Writing parameter values

Unused bytes in the data field are shown with a slash in the graphic. The content of these data fields is not defined.

ccd coding The table below shows the command code for writing parameter values. It depends on the message type and the transmitted data length.

Message type

Data length used

 

 

 

 

4 bytes

3 bytes

2 bytes

1 byte

 

 

 

 

 

 

 

Write request

23h

27h

2Bh

2Fh

Transmitting param-

 

 

 

 

 

eters

 

 

 

 

 

 

Write response

60h

60h

60h

60h

Confirmation

Error response

80h

80h

80h

80h

Error

Table 3.5 Command code for writing parameter values

0198441113586, V2.01, 11.2008

28

Fieldbus interface

Page 28
Image 28
Schneider Electric DS301 manual Reading and writing data, Message type Data length used Bytes