Connection to a fieldbus
6.3 Communication via PROFIBUS
6.3.3.2
Data structure of the parameter channel
Parameter channel
You can write and read parameter values via the parameter channel, e.g. in order to monitor
process data. The parameter channel always comprises four words.
Figure 6-3
Parameter identifier (PKE), 1st word
The parameter identifier (PKE) contains 16 bits.
Figure 6-4
● Bits 12 to 15 (AK) contain the request or response identifier.
● Bit 11 (SPM) is reserved and is always 0.
● Bits 0 to 10 (PNU) contain parameter numbers 1 ... 1999. For parameter numbers ≥ 2000
The meaning of the request identifier for request telegrams (control → inverter) is explained
in the following table.
Table 6- 13
Request
identifier
0
1
2
3
4
6
118
Structure of the parameter channel
PKE - 1st word in parameter channel
an offset must be added that is defined in the 2nd word of the parameter channel (IND).
Request identifier (control → inverter)
No request
Request parameter value
Change parameter value (word)
Change parameter value (double word)
Request descriptive element
Request parameter value (field)
Description
1)
1)
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA
Response
identifier
positive
negative
0
7 / 8
1 / 2
↑
1
|
2
|
3
|
4 / 5
|