What should I pay attention to when assigning addresses to I / O modules (centralized or distributed) on the S7CPU?

Note that the created data area (such as a double word) can not be configured on the boundary of the process image because only the area below the boundary can be read into the process image in the data block, so it is not possible to access from the process image data. Thus, these configuration rules do not support this situation: for example, configure an input double word on the 254 address of a 256-byte input process image. If such a location is required, the size of the process image must be adjusted accordingly (in the Properties of the CPU).