A connection between your PC/programming device and the PLC cannot be established.

PLC是Programmable Logic Controller的缩写，就是可编程逻辑控制器。

这个提示是指你的西门子工业控制编程无法跟可编程逻辑控制器（Device）连接上。查查看连接，或者重起系统看看。不然的话就要查看程序支持你的Device了。

你的电脑/程序设备和plc之间无法建立（某个）连接。

通讯没设置好吧？？通讯地址和波特率从新设置一下

重装驱动。重新联线，不行就把整个软件重装一次

Restart the Amprolyzer by double-clicking the Amprolyzer icon on the desktop. Select the "Add Bus ..." button, because you have to reinstall the driver to get to the display of the Amprolyzer operator controls. Select the hardware (here CP5611) and acknowledge with "OK". Close the Amprolyzer again by clicking the "Close" button.

大致意思是重启那个Amprolyzer,重装驱动

http://support.automation.siemens.com/TW/llisapi.dll?func=cslib.csinfo&objId=22818963&load=treecontent&display=p