procedure TfrmABSinterface.GetAvailableDPI;
var
  i, iMaxX, IMaxY, Imax : integer;
begin

     try
           {----- Get Maximum Available Resolution (DPI) from the device. }
        iMaxX := Trunc(frmMain.ImageEnMView1.MIO.TwainParams.XResolution.RangeMax);
        iMaxY := Trunc(frmMain.ImageEnMView1.Mio.TWainParams.YResolution.RangeMax);
           {----- Pick the lowest between X and Y because we only display one value.}
        if iMaxX > iMaxY then
          iMax := iMaxY
        else
          iMax := iMaxX;
           {----- The array max is 10 so don't go beyond.}
        if iMax > 10 then
          iMax := 10;
           {----- We can't read DPI. ASSUME scanner can 300 DPI.}
        if iMax = 0 then
          iMax := 4;
           {----- Populate the combobox items}
        For i := 0 to iMax do
        begin
          if DPI[i] > DPI[iMax] then
            Break;
          cboResolution.Items.Add( IntToStr(DPI[i]) + ' Dots per inch.');
        end;
           {----- Set the cbo text value to match one in the list.}
        if iMax >= 2 then
          cboResolution.ItemIndex := 2
        else
          cboResolution.ItemIndex := iMax;
     except
        on E: Exception do
        begin
          ShowMessage(E.Message);
        end;
     end;
end;

FloatToStr(frmMain.ImageEnMView1.MIO.AcquireParams.XResolution));

frmMain.ImageEnMView1.MIO.AcquireParams.XResolution := 2400.0;