因为我在看《What are the options for connecting a PC station to Industrial Ethernet or PROFIBUS via the SIMATIC NET OPC server?》文档时，上面说，
The following communication services are available for communication via PROFIBUS:
FDL Protocol时，
The FDL protocol can be used for data exchange with S7 stations and S5 stations. You need one of the following SIMATIC NET PC software
packages if you want to use the FDL protocol including SIMATIC NET OPC server for data exchange:

* SOFTNET DP - for communication via CP5611 (A2), CP5621 or CP551x.
* CP5613/5614 (A2) - here you do not need any other software, because the protocol driver is supplied with the hardware.

按照我原来的理解，安装了SIMATICNET 后，插入CP5611就行了。
结果上面文档又弄出这个SOFTNET ，这个把小弟搞糊涂了