Function 6: writing an analog output
Function 6 can be used to access the output process image and the interface.
The first analog output is written with function 6. The analog outputs start at an offset of 0x0800. Here again the offset always describes a word. This means offset 0x0803 refers to the fourth word in the output process image.
Query
|
Byte Name | Modbus RTU | Modbus ASCII | ||
|---|---|---|---|---|
Start - frame | - | - | ":" | 0x3A |
Address | 11 | 0x0B | "0B" | 0x30, 0x42 |
Function code | 6 | 0x06 | "06" | 0x30, 0x36 |
Start address high | 8 | 0x08 | "08" | 0x30, 0x36 |
Start address low | 0 | 0x00 | "00" | 0x30, 0x30 |
Data high | 63 | 0x3F | "3F" | 0x33, 0x46 |
Data low | 255 | 0xFF | "FF" | 0x46, 0x46 |
Error check, LRC/CRC |
| 0xDA, 0xB0 | "A9" | 0x41, 0x39 |
End - frame |
| t1-t2-t3 | CRLF | 0x0D, 0x0A |
The Fieldbus Coupler Box responds with the same telegram and confirmation of the received data.
Response
|
Byte Name | Modbus RTU | Modbus ASCII | ||
|---|---|---|---|---|
Start - frame | - | - | ":" | 0x3A |
Address | 11 | 0x0B | "0B" | 0x30, 0x42 |
Function code | 6 | 0x06 | "06" | 0x30, 0x36 |
Start address high | 8 | 0x08 | "08" | 0x30, 0x36 |
Start address low | 0 | 0x00 | "00" | 0x30, 0x30 |
Data high | 63 | 0x3F | "3F" | 0x33, 0x46 |
Data low | 255 | 0xFF | "FF" | 0x46, 0x46 |
Error check, LRC/CRC |
| 0xDA, 0xB0 | "A9" | 0x41, 0x39 |
End - frame |
| t1-t2-t3 | CRLF | 0x0D, 0x0A |