I have this one D410 (V 4.4, SINAMICS V4.7) that I cannot get the real time clock to retain.  I can set it to PG time (TIA Portal V13 SP1, Scout TIA V4.4) and download the hardware configuration.  Hoever, if I turn off power, the clock resets to some date in either 2019 or 2024.  I'm pulling my hair out trying to figure this out.  I've never had this happen before, but I normally use D435's

Time is UDT +8 if that makes a difference. 

omg

And of course nothing is writing the RTC and there isn't any external synchronization (NTP,PLC,ecc).

We use RTC in our D425-2 and D410-2 and we have never had problems because the RTC was maintained, even if we set or not preset it with computer... Also the fact that date is post poned to "future" is curious... It should go back to 1999 (if i remember correctly) which is the "day 0" of Simotion when you buy it.

Also I think that that RTC value is read by a quartz clock and nothing much more...

Maybe ChristophD can tell you something to watch during the startup (diagnostic buffer)...

GL m8

I'll be back at the jobsite in a few days and I'll make a copy of the diagnostic log.  Nothing I saw in it earlier raised any concerns.

It's my program and nothing is writing to the RTC.  I've been having some other strange problems with this particular unit.  It might be defective.

I attached the (shortened) diagnostic log from the 13th.  Events 81-94 are from when I arrived.  Events 15-80 are after I changed the RTC (Set clock, download HW to 410, Save RAM to ROM) and powered down.  Events 1-14 are after power up.  Back to 2024.

I replaced the unit and its fine.  I guess this one is defective.