Hello

I have a problem with OP 77A panels. I find some panels freez while running and they need to be restarted. Also, on many panels, Ioften findalarm which areno longer presentand acknowledge but is still present in alarm list. After I disconnect OP panel from power supply and connect again, it disappears from alarm list.It is wery often problem. Iam working with WinCC flexible 2007 standard. Can anyone help me?

Thanks in advance for any help and suggestion.