出现故障时请把CPU故障诊断信息发上来。

哈哈这种问题我遇到过，首先查看CPU诊断信息，判断哪几个DP站掉线，然后从掉线的地方最好加一个中继站，分出两路再进行测试，运行一段时间看看是否会出现掉线。

我当时的情况是：6号，7号，15号站出现掉线，后来加中继站，但是问题没有解决，因为6,7,15号站是一路下来的，然后开始怀疑电源，模块等等有问题，全换了也没能解决问题，最后给6号站从中继站单独走一路，7，15号从中继站走另一路，困扰了我半年的问题总算尘埃落定，那真的大快人心呀。

Diagnostic buffer of module CPU 315F-2PN/DP

Order No./ Description          Component                       Version                      

6ES7 315-2FJ14-0AB0             Hardware                        3                            

- - -                           Firmware                        V 3.2.3                      

Boot Loader                     Firmware expansion              A 32.9.9                     

Rack:                           0

Slot:                           2

Serial number: S C-B4UF40262011

Event 1 of 10:  Event ID 16# 38C4

Distributed I/Os: station return

Address of the affected DP slave: station number:    6

DP master system ID:      1

Log. base address of the DP slave: Input address:  2042

Log. base address of the DP master:   2047

Requested OB: Rack failure OB (OB86)

Priority class: 26

External error, Outgoing event

09:46:32.818 AM  05/26/2014

(Coding: 16# 38C4  1A56  C054  07FF  07FA  0106)

Event 2 of 10:  Event ID 16# 79E5

F-I/O passivated

- Monitoring time exceeded at the safety frame detected in the F-CPU

Logical base address:     32

F-I/O database number:    554

External error, Incoming event

09:46:32.625 AM  05/26/2014

(Coding: 16# 79E5  9F00  C47A  022A  0020  0002)

Event 3 of 10:  Event ID 16# 39C4

Distributed I/Os: station Failure

Address of the affected DP slave: station number:    6

DP master system ID:      1

Log. base address of the DP slave: Input address:  2042

Log. base address of the DP master:   2047

Requested OB: Rack failure OB (OB86)

Priority class: 26

External error, Incoming event

09:46:32.470 AM  05/26/2014

(Coding: 16# 39C4  1A56  C054  07FF  07FA  0106)