我在检查CPU无法运行的原因，有一个错误;

Parameter assignment error in parameters for central S7 modules

subrack 0

Slot    6

Error type: Slot configured for CPU is not occupied or is occupied by a place holder, or a station has failed or the switched I/O system has lost its redundancy. 

Data record number: 255

Operating mode: STOP (internal)

External error, Incoming event

换了第6个插槽的全新的AO模块还是不好，然后我就往前把第5个模块的DIO和第9个模块的DIO互换，当不插上第9个模块的时候可以运行，CPU也不亮红灯，比较好奇为什么不报错呢？另外就是报错的提示和实际不一致怎么去查。