OPC-System.Runtime.InteropServices.COMException:“Error HRESULT E_FAIL has been returned from a call to a COM component.”
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。