WriteCoils (WriteCoils sss) Problem

[guverdik]

procedure TfrmMain.btnWriteClick(Sender: TObject);
var iAmount: Integer; Data: array[0..4096] of Boolean; i: Integer;
begin
mctPLC.Host := edtIPAddress.Text;
iAmount := StrToInt(edtReadAmount.Text);

if CheckBox1.Checked then Data[0] := True else Data[0] := False;
if CheckBox2.Checked then Data[1] := True else Data[1] := False;
if CheckBox3.Checked then Data[2] := True else Data[2] := False;
if CheckBox4.Checked then Data[3] := True else Data[3] := False;
if CheckBox5.Checked then Data[4] := True else Data[4] := False;
if CheckBox6.Checked then Data[5] := True else Data[5] := False;
if CheckBox7.Checked then Data[6] := True else Data[6] := False;
if CheckBox8.Checked then Data[7] := True else Data[7] := False;
if mctPLC.WriteCoils(StrToInt(edtWriteReg.Text), iAmount, Data) then
Label6.Caption := 'PLC Write Success!' else Label6.Caption := 'PLC Write Not Success!';

But not success. What is the problem?