Hello dear experts. I fouded strange behaviour of the SINAMICS s120, that i can't to solve.

We have 4 inverters in the network, all of them are connected according to the TOPOLOGY . You can find it out at the screenshots (sory for the quality of the pictures). All of them responding at ping command from my laptop and all of them i can find in the list of accessible online devices. But two of them returs allarm in TIA portal like "Not reachable". I tried to recompile all project, reload all hardware and also i tried to reset to factory settings - no result, always the same. As you can see, the firmware and version are the same for REACHABLE and NOT REACHABLE device. 

At the not reachable device the led COM is blinking

I finised my thinks how to solve this issue. Have you an ideas?

TIA v15.1

Inverters 6SL3 040-1LA01-0AA0

Closed cause question posted twice.

The second thread with the subject S120, not reachable but ping is ok and exist in list "ONLINE DEVICES" is published within the conference SINAMICS S.