现场一共八套西门子S7系列的PLC，通过以太网（星形）网络通讯，但是昨天出现一次问题，其中一台PLC300的系统断电后，居然影响到另外一台400的plc停机，重新启动后正常，其他PLC运行正常。查看停机的PLC诊断信息如下：

Diagnostic buffer of module CPU 414-2 DP

Order No./ Description        Component                     Version                      

6ES7 414-2XK05-0AB0           Hardware                      2                            

- - -                         Firmware                      V 5.1.1                      

Rack:                         0

Slot:                         3

Event 1 of 120:  Event ID 16# 4302

Mode transition from STARTUP to RUN

Startup information:

- Time for time stamp at the last backed up power on

- Single processor operation

Current/last startup type:

- Warm restart triggered by switch setting

Permissibility of certain startup types:

- Manual warm restart permitted

Last valid operation or setting of automatic startup type at power on:

- Warm restart triggered by switch setting

Previous operating mode: STARTUP (warm restart)

Requested operating mode: RUN

Incoming event

10:09:29.801 PM  09/11/2014

Event 2 of 120:  Event ID 16# 1381

Request for manual warm restart

STOP due to: STOP caused by stop switch being activated

Startup information:

- Startup without modified system configuration

- Difference between setpoint and actual configuration

- Time for time stamp at the last backed up power on

- Single processor operation

Current/last startup type:

- Warm restart triggered by switch setting

Permissibility of certain startup types:

- Manual warm restart permitted

Last valid operation or setting of automatic startup type at power on:

- Warm restart triggered by switch setting

Requested OB: Startup OB (OB100)

Priority class: 27

Incoming event

10:09:28.747 PM  09/11/2014

Event 3 of 120:  Event ID 16# 4301

Mode transition from STOP to STARTUP

STOP due to: STOP caused by stop switch being activated

Startup information:

- Time for time stamp at the last backed up power on

- Single processor operation

Current/last startup type:

- Warm restart triggered by switch setting

Permissibility of certain startup types:

- Manual warm restart permitted

Last valid operation or setting of the automatic startup type at power on:

- Warm restart triggered by switch setting

Previous operating mode: STOP (internal)

Requested operating mode: STARTUP (warm restart)

Incoming event

10:09:28.718 PM  09/11/2014

Event 4 of 120:  Event ID 16# 530D

New startup information in STOP mode

Startup prevented by:

- Cold restart or warm restart necessary

Startup information:

- Time for time stamp at the last backed up power on

- Single processor operation

Current/last startup type:

- Warm restart triggered via MPI

Permissibility of certain startup types:

- Manual warm restart permitted

Last valid operation or setting of automatic startup type at power on:

- Warm restart triggered by switch setting

Operating mode: STOP (internal)

Incoming event

10:09:28.718 PM  09/11/2014

Event 5 of 120:  Event ID 16# 530D

New startup information in STOP mode

Startup prevented by:

- STOP request exists

- Keyswitch set to STOP

- Cold restart or warm restart necessary

Startup information:

- Time for time stamp at the last backed up power on

- Single processor operation

Current/last startup type:

- Warm restart triggered via MPI

Permissibility of certain startup types:

- Manual warm restart permitted

Last valid operation or setting of automatic startup type at power on:

- No startup type/following memory reset

Operating mode: STOP (internal)

Incoming event

10:09:24.504 PM  09/11/2014

Event 6 of 120:  Event ID 16# 4303

STOP caused by stop switch being activated

Previous operating mode: RUN

Requested operating mode: STOP (internal)

Incoming event

10:09:24.500 PM  09/11/2014