Siemens SINAMICS G120 CU230P-2, Operating Instructions Manual, Page: 115 / 346

Configuring the fieldbus
6.1 Communication via PROFIBUS
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
113
6.1.5 Acyclic communication
As from performance level DP-V1, PROFIBUS communications offer acyclic data
communications apart from cyclic communications. You can parameterize and troubleshoot
(diagnostics) the inverter via acyclic data transfer. Acyclic data is transferred in parallel with
cyclic data transfer but with a lower priority.
The inverter supports the following data transfer types:
●
Reading and writing parameters via "data set 47" (up to 240 bytes per write or read
request)
● Reading-out profile-specific parameters
● Data exchange with a SIMATIC HMI (Human Machine Interface)
You can find a STEP 7 program example for acyclic data transfer in Section STEP 7
program example for acyclic communication (Page 330).
6.1.5.1 Reading and changing parameters via data set 47
Reading parameter values
Table 6- 15 Request to read parameters
Data block Byte n Bytes n + 1 n
Reference
01 hex ... FF hex
01 hex: Read request 0 Header
01 hex Numberof parameters (m)
01 hex ... 27 hex
2
Attribute
10 hex:
Parameter value
20 hex:
Parameter description
Number of indices
00 hex ... EA hex
(for parameters without index: 00 hex)
4
Parameter number
0001 hex ... FFFF hex
6
Number of the 1st index
0000 hex ... FFFF hex
(for parameters without index: 0000 hex)
8
Address, parameter 1
… …
Address, parameter 2 … …
… … …
Address, parameter m … …