Hi,

my system is composed by a CPU 315-2 DP (6ES7 315-2AH14-0AB0) and a CP 342-5 DP (6GK7 342-5DA03-0XE0) configured as MASTER, connected with 6 slave. During the course of my program I need to know the PROFIBUS address of the module CP 342-5 (set in HW configuration and equal to 9). Can I get that information by the use of the system blocks, for example with the SFC51 "RDSYSST" (although I think can not be used on this module) or with the FC3 (DP_DIAG) properly configured? If with these blocks is not possible you could indicate me which I use or how i can get that information. Thanks in advance for your kind availability. 

Hello,

I would try to read the system list  with SSL-ID of W#16#0195
It returns a record where one of the informations is the DP Master address.

See annex (extract from system manual)