Error HRESULT E_FAIL has been returned from a call to a COM component的错误提示，还是因为OPC配置，这次是红框中标签定义错误，应该是PLC2：PLC_PRG_W，send一个不存在的item，因此出现调用com出错。
OPC-System.Runtime.InteropServices.COMException:“Error HRESULT E_FAIL has been returned from a call to a COM component.”
原文：https://www.cnblogs.com/runningsoybean/p/11510188.html
