我有一个400的plc，通过集成的dp口，和2个上位机的cp5613卡通讯，用无dp的方式，s7连接，现在上位机通讯不稳定，一部分数据经常读不到，我查了400的诊断信息，有err但是在run，可是这个诊断信息真的是看不懂！都outgoing了，怎么还err呢，而且这么多诊断信息，就两个内容，我现在拷贝过来，大家帮我看看：

Diagnostic buffer of module CPU 416-2 DP

Order No./ Des cription Component Version
6ES7 416-2XK02-0AB0 Hardware 8
- - - Firmware V 3.1.3

Rack: 0
Slot: 3


Event 1 of 120: Event ID 16# 6881
Interface error leaving state
Interface ID: X1, MPI/DP/PROFINET
Operating mode: RUN
External error, Outgoing event
10:29:44.123 AM 10/31/2008


Event 2 of 120: Event ID 16# 6981
Interface error entering state
Interface ID: X1, MPI/DP/PROFINET
Operating mode: RUN
External error, Incoming event
10:29:44.081 AM 10/31/2008