invalid firmware reaction in case an alarm is received a second time (e.g. in case of disturbed network connection)

If an IO Device sends an alarm to the IO Controller and the IO Controller has sent the transport acknowledge and the positive applicative alarm data acknowledge.

If now both frames from IO Controller are not received by IO Device (e.g. due to disturbed network connection) the IO Device will now resend the original alarm to IO CoNtroller.

According to Profinet specification this situation shall be handled by IO Controller by simply again send a transport acknowledge for the received alarm.

Current IO Controller implementation aborts the AR to the IO Device instead which is unexpected and not covered by Profinet specification.