This is small Example. I had a POS Application in VB6 with this code. Me.EpsonFPHostControl1.SendCommand While EpsonFPHostControl1.State = EFP_S_Busy DoEvents Wend This code is almost the same in VB.NET Me.AxEpsonFPHostControl1.SendCommand() While AxEpsonFPHostControl1.CtlState = EpsonFPHostControlX.TxFiscalState.EFP_S_Busy Application.DoEvents() End While