小弟有个项目。去年下半年开始运行，一切正常。可是最近出了个严重的问题。PLC正常运行过程中，突然停车。CPU进入STOP状态，导致我的整个设备全部停车。手动恢复一下（CPU拨码开关从RUN-STOP-RUN）PLC又可以运行。以下是我的配置和诊断报告。还请各位高手帮忙！

硬件配置：电源：PS307 10A
CPU:313C-2DP
模块：IM365
SM321 DI32*DC24V 5块
SM322 DO32*DC24V/0.5A 3块
IM365
SM332 AO4*12Bit 3块
SM331 AI8*12Bit 3块

诊断报告：
Event 33 of 100: Event ID 16# 494D
STOP caused by I/O error
No relevance for user (Z1): 0000
No relevance for user (Z2): 5752 (Z3): 2101
Previous operating mode: RUN
Requested
operating mode: STOP (internal)
External error, Incoming event

帮助文档：
Help on Event 4x4D

Possible causes:
S7-300:A module was removed or inserted illegally.


S7-400:
Failure of the module inserted/removed monitoring or error in interrupt servicing due to a defective module or due to removing or inserting a module illegally.

To correct or avoid errors:

Based on the system status lists, check the current I/O configuration detected by the CPU. Compare this with the existing configuration to see whether there are any defective modules.

Bus error in the local or distributed I/O

To correct or avoid error:

To remove the error, you must switch the device off and then on again. If the error still occurs, check the bus connection and interface modules in the distributed I/O. Make a note of the HEX code marked as "Not user-relevant" in the detailed information for the diagnostic buffer entry and contact your manufacturer.


This error can occur when an expansion device is switched off, for example, if an IM module is defective.

To Correct or Avoid Error:
Replace the defective module.


看了帮助也没有人移动I/O模块啊。我把365换成了360/361还换了几个总线连接器。可以还是会出现CPU停机的情况。我这个设备有个特点就是会产生高频放电的现象，我观察了一下，如果产生强烈的放电后，CPU就STOP了。恢复后即使不在放电也很容易出现STOP。如果设备停了一阵子没用后，再运行后又能坚持几天正常运行，之后就又会出现CPU停机的情况。

这种情况是干扰引起的吗？如果是的话可是去年一直运行的都很正常啊？如果是PLC硬件有问题了，诊断里也没有具体说明？

哪位高手遇到过类似的问题吗？帮小弟出出主意吧！快愁死我了！