Beckhoff BC9000 Documentation page 70

Fieldbus system
7.5.4.6 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
Function code
Start address high
Start address low
Data high
Data low
The coupler answers with the same telegram.
Response
Byte name
Function code
Start address high
Start address low
Data high
Data low
7.5.4.7 Preset single register (Function 6)
The function Preset singles register can be used to access the output or flag process image (only for
controllers) and the Modbus TCP interface [} 65].
Function 6 writes the first output word. The 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
Function code
Start address high
Start address low
Data high
Data low
The Fieldbus Coupler replies with the same telegram and confirmation of the received value.
Response
Byte name
Function code
Start address high
Start address low
Data high
Data low
70
Sample
5
0
2
255
0
Sample
5
0
2
255
0
Sample
6
8
0
63
255
Sample
6
8
0
63
255
Version: 4.0.0 BC9000 and BC9100