本人这里有一台数控龙门铣，在Y Z W 三向同时松开的情况下会不定时出现：

2000 PLC通信失败

3000 急停

810004 PLC停止/中止错误

三个报警。只要这三向同时松开，不管开不开车都会报警。但是只松Y Z 或只松Z W或Y W 中任意两向或者一向都不会报警。

开始认为是24V的线的虚接的地方，但所有的线都查到了报警依就出现。

后来又检查了一下PLC程序，用TOOLBOX5.1生成标准块，将PLC总清，重新传了一遍。但现在报警依就会出现。本人百思不得其解，请各位大虾指教。



我已经查看过Diagnosis buffer
其内容如下：
Diagnostic buffer of module CPU 315-2 DP

Order No./ Des cription Component Version
6ES7 315-2AF03-0AB0 Hardware 1
12.30.09 09.07.2002 Firmware V 1.2.0


Event 1 of 100: Event ID 16# 494D
STOP caused by I/O error
No relevance for user (Z1): 0000
No relevance for user (Z2): 0000 (Z3): 0000
Previous operating mode: RUN
Requested operating mode: STOP (internal)
External error, Incoming event
11:20:14:150 am 05/14/04
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.

但是我还是不太明白，PCI电缆的接头我已经检查过了，没有问题，
我还是感觉有些无从下手，还请大虾指教！非常感激！