Diagnostic buffer of module CPU 315-2 DP

Order No./ Des cription Component Version
6ES7 315-2AF03-0AB0 Hardware 1
- - - Firmware V 1.2.0

Rack: 0
Slot: 2
Event 1 of 10: Event ID 16# 3842
Module OK
Module type: Distributed I/0s
Input address: 1018
User information available
Diagnostic interrupt from substitute
Requested OB: Diagnostic interrupt OB (OB82)
Priority class: 26
External error, Outgoing event
04:43:52.124 PM 10/09/2011

这是什么意思呢？不知该查什么地方？