procedure TChatForm.btn1Click(Sender: TObject);
begin
	qryFireEvents.SQL.Clear;

	if qryFireEvents.Connection.ConnectionMetaDataIntf.EventSupported then begin
		qryFireEvents.Connection.ExecSQL('delete from dbo.Test');
		qryFireEvents.Connection.ExecSQL('insert into dbo.Test values (1, ''Test1'')');

		qryFireEvents.Connection.ExecSQL('delete from dbo.Test2');
		qryFireEvents.Connection.ExecSQL('insert into dbo.Test2 values (1, ''Test2'')');

	end;
end;

procedure TChatForm.ea1Alert(ASender: TFDCustomEventAlerter;
  const AEventName: string; const AArgument: Variant);
var
	i: Integer;
	sArgs: String;
begin
	if VarIsArray(AArgument) then
  begin
		sArgs := '';
		for i := VarArrayLowBound(AArgument, 1) to VarArrayHighBound(AArgument, 1) do
    begin
			if sArgs <> '' then
				sArgs := sArgs + ', ';
			sArgs := sArgs + VarToStr(AArgument[i]);
		end;
	end
	else if VarIsNull(AArgument) then sArgs := '<NULL>'
	else if VarIsEmpty(AArgument) then sArgs := '<UNASSIGNED>'
	else sArgs := VarToStr(AArgument);
	Mem1.Lines.Add('Event - [' + AEventName + '] - [' + sArgs + ']');

end;

procedure TChatForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
	if not ea1.Active then Exit;
	ea1.Unregister;
end;

procedure TChatForm.FormCreate(Sender: TObject);
begin
	if ea1.Active then 	Exit;

	ea1.Names.Clear;

	ea1.Names.Add('QUEUE=?');
	ea1.Names.Add('SERVICE=?');
	ea1.Names.Add('CHANGE1=ev1;select id, name from dbo.Test');
	ea1.Names.Add('CHANGE2=ev2;select id, name from dbo.Test2');
	ea1.Options.Synchronize := True;
	ea1.Register;
end;

Project warehouse.exe raised exception class EFDException with message '[FireDAC][Phys][MSSQL]-326. Cannot perform the action, because the previous action is in 
progress'.