在硬件组台态时，CPU选315-2AG10后下载，一切正常；再添加一PROFIBUS线（DP Master）后再下载，出现以下错误提示：

1 System error.

2 Cannot load SDB 122.

3 he system data cannot be loaded to module

CPU315-2DP(1) - (R0/S2) of station SIMATIC

300 Station.

Look under details or try to determine the

cause for the problem using the diagnostic

buffer of the module.