Refer to Diagnostic class (standard): 1
The Ext. diagnosis start indicates the start of the Fast Device Replacement (FDR) operation. With the Ext diagnosis end, the end of a Fast Device Replacement is indicated. Between start and end, the activities of the Fast Device Replacement are recorded. An entry with the version number in the ext. diagnosis signals that the firmware was exchanged successfully on the concerned device. If there are no entries between start and end, then the Fast Device Replacement detected in the status check/1 that an exchange of the firmware on the devices does not need to be performed.