Force Single Coil (Function 5)
The Force Single Coil function can be used to write a digital output. The third digital output is written in this example. The digital outputs start at address 0x0000. The digital value is located in Data high. To switch the output on, Data high must contain the value 0xFF, while 0x00 is used to switch the output off again. Data low must contain the value 0x00.
Query
|
Byte Name |
Modbus RTU |
Modbus ASCII | ||
|---|---|---|---|---|
|
Start - Frame |
- |
- |
":" |
0x3A |
|
Address |
11 |
0x0B |
"0B" |
0x30, 0x42 |
|
Function-Code |
5 |
0x05 |
"05" |
0x30, 0x35 |
|
Start-Address high |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Start-Address low |
2 |
0x02 |
"02" |
0x30, 0x32 |
|
Data high |
255 |
0xFF |
"FF" |
0x46, 0x46 |
|
Data low |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Error Check, LRC/CRC |
|
0x2D, 0x50 |
"EF" |
0x45, 0x46 |
|
End -Frame |
|
t1-t2-t3 |
CRLF |
0x0D, 0x0A |
The coupler answers with the same telegram.
Response
|
Byte Name |
Modbus RTU |
Modbus ASCII | ||
|---|---|---|---|---|
|
Start - Frame |
- |
- |
":" |
0x3A |
|
Address |
11 |
0x0B |
"0B" |
0x30, 0x42 |
|
Function-Code |
5 |
0x05 |
"05" |
0x30, 0x35 |
|
Start-Address high |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Start-Address low |
2 |
0x02 |
"02" |
0x30, 0x32 |
|
Data high |
255 |
0xFF |
"FF" |
0x46, 0x46 |
|
Data low |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Error Check, LRC/CRC |
|
0x2D, 0x50 |
"EF" |
0x45, 0x46 |
|
End - Frame |
|
t1-t2-t3 |
CRLF |
0x0D, 0x0A |