How to programmatically unplug & replug an arbitrary USB device?

Question

I\'m trying to fix a non-responsive USB device that\'s masquerading as a virtual COM port. Manual replugging works, but there may be up to 12 of these units. Is there an API

Answer 1

You can use the C# Hardware Helper Lib and add the ResetDevice function.

public bool ResetDevice( IntPtr hDevInfo, IntPtr devInfoData )  
// Need to add  
// public const int DICS_PROPCHANGE = ((0x00000003));   
// at the public class Native under //PARMS  
int szOfPcp;  
IntPtr ptrToPcp;  
int szDevInfoData;  
IntPtr ptrToDevInfoData;  

Native.SP_PROPCHANGE_PARAMS pcp = new Native.SP_PROPCHANGE_PARAMS();  
pcp.ClassInstallHeader.cbSize = Marshal.SizeOf(typeof(Native.SP_CLASSINSTALL_HEADER));  
pcp.ClassInstallHeader.InstallFunction = Native.DIF_PROPERTYCHANGE;  
pcp.StateChange = Native.DICS_PROPCHANGE; // for reset  
pcp.Scope = Native.DICS_FLAG_CONFIGSPECIFIC;  
pcp.HwProfile = 0;  

szOfPcp = Marshal.SizeOf(pcp);  
ptrToPcp = Marshal.AllocHGlobal(szOfPcp);  
Marshal.StructureToPtr(pcp, ptrToPcp, true);  
szDevInfoData = Marshal.SizeOf(devInfoData);  
ptrToDevInfoData = Marshal.AllocHGlobal(szDevInfoData);  
Marshal.StructureToPtr(devInfoData, ptrToDevInfoData, true);  

bool rslt1 = Native.SetupDiSetClassInstallParams(hDevInfo, ptrToDevInfoData, ptrToPcp,   Marshal.SizeOf(typeof(Native.SP_PROPCHANGE_PARAMS)));  
bool rstl2 = Native.SetupDiCallClassInstaller(Native.DIF_PROPERTYCHANGE, hDevInfo,   ptrToDevInfoData);  

if (rslt1 && rstl2)  
{  
    return true;  
}  
return false;  
}