Failed to open the usb port LPT1

Hi,

I am trying to print some text from MK500(windows CE5.0) to QL220 Plus and QLn220.

 

MK500 to QL220 Plus is working fine. But when I connect to Qln220 I get following error while opening the connection.

 

Failed to open the USB port: LPT1: ,Stack Trace -   at ZSDK_API.Comm.UsbPrinterConnection.Open()

   at abc.ZebraPrint.InitializePrinterConnection()

   at abc.ZebraPrint..ctor()

   at abc.ZebraPrint.GetInstance()

   at abc.PortPanelPresenter..ctor(IView view)

   at abc.View.MainView.ReaderFormLoad(Object sender, EventArgs e)

   at System.Windows.Forms.Form.OnLoad(EventArgs e)

   at System.Windows.Forms.Form._SetVisibleNotify(Boolean fVis)

   at System.Windows.Forms.Control.set_Visible(Boolean value)

   at System.Windows.Forms.Application.Run(Form fm)

   at abc.abc.Program.Main().

 

What am I missing?

Thanks,

Gopal