data change handler in C#

I will be used the 128 data change handler for taking the updates of the OPC server but only 2 are working fines, but another is not working. It will stop af开发者_运维百科ter 15 min. Please tell me how many data change handlers will work in one application. Data change handler working is same as timer thread; it will be invoke after the 250 milliseconds.

private void DataChangeHandler(object sender, DataChangeEventArgs e)
{
    // The invoke handling is only required when
    // the callback handler writes data into Windows dialogs
    try
    {                           
        if (InvokeRequired)
        {
            BeginInvoke(new DataChangeEventHandler(DataChangeHandler),
                new object[] { sender, e });
            //  return;
        }
        if (parameter.X == 0)
        {
            parameter.X = 1;
            Thread th = new Thread(param.update);
            th.Start(e);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}