Beckhoff BC9000 Documentation page 73

Response
The Bus Coupler answers with the same telegram.
Byte name
Function code
Start address high
Start address low
Length high
Length low
7.5.4.10 Preset single register (Function 16)
The Preset multiple register function can be used to write a number of outputs. The first two analog output
words are written in this example. The outputs start at an offset of 0x0800. Here the offset always describes
a word. Offset 0x0003 writes to the fourth word in the output process image. The length indicates the number
of words, and the Byte count is formed from the combination of all the bytes that are to be written.
Sample: 4 words - correspond to a byte count of 8
The data bytes contain the values for the analog outputs. In this example, two words are to be written. The
first word is to receive the value 0x7FFF, and the second word is to receive the value 0x3FFF.
Query
Byte name
Function code
Start address high
Start address low
Length high
Length low
Byte count
Data 1 byte 1
Date 1 byte 2
Date 2 byte 1
Data 2 byte 2
Response
The coupler replies with the start address and the length of the transmitted words.
Byte name
Function code
Start address high
Start address low
Length high
Length low
7.5.4.11 Read / write registers (Function 23)
A number of analog outputs can be written and a number of analog inputs read with one telegram using the
Read / write registers function. In this example the first two analog output words are written, and the first two
analog inputs are read. The analog outputs start at offset 0x0800, while the inputs start at offset 0x0000.
BC9000 and BC9100
Sample
15
0
0
0
20
Sample
16
8
0
0
2
4
127
255
63
255
Sample
16
8
0
0
2
Version: 4.0.0
Fieldbus system
73