一套S7-300系统，早上发现CPU已经Stop了。开关处于RUN位置，搬到STOP位置后再扳到RUN，CPU已经不能run了。SF故障等亮。因为没有源程序，所以用MPI编程电缆接上CPU把源程序拷贝下来，还能够进入硬件配置。我认为CPU应该没有问题。用IM365扩展IO接口。如果是IO接口有问题，不至于CPU启动不起来。能是电源模块出了问题吗？请各位帮助分析一下。谢谢！以下是拷贝的诊断信息：
Event 5 of 100: Event ID 16# 4300
Power on backed up
Previous operating mode: No voltage
Requested operating mode: STOP (own initialization)
Incoming event
09:01:47:644 pm 08/03/00


Event 6 of 100: Event ID 16# 494E
Power failure
Previous operating mode: STOP (internal)
Requested operating mode: No voltage
External error, Incoming event
09:01:30:580 pm 08/03/00


Event 7 of 100: Event ID 16# 494D
STOP caused by I/O error
No relevance for user (Z1): 0000
No relevance for user (Z2): 0050 (Z3): 4555
Previous operating mode: STOP (internal)
Requested operating mode: STOP (internal)
External error, Incoming event
09:01:08:119 pm 08/03/00