USB-6501 continuously toggling T/F to a single channel in a C# program

[eafRockStarr]

Hi, I am pretty green at NI DAQ-MX development.  I have inherited a simple labview project that continuously toggles a channel on a USB-6501 device to T/F for 5,000 cycles with a configurable number of sec pause between each set that I have converted to a C# WinForm project.  I am doing the toggling of the channel in a BackGroundWorker's DoWork event.  Occasionally the NationalInstruments.DAQmx.Task object throws an Exception:

Task Name: _unnamedTask<485>

Status Code: -50405

What should I do in this instance?  From a programming perspective should I be handling the Exception and trying to set up to write to the channel again?  Currently, I am just throwing the exception because I am not sure.  It can take days of testing for the exception to happen, but it never occured with the labview project..

Also I would to confirm I am doing the best practice of continuously creating a new DAQmx.Task and DigitalSingleChannelWriter objects for each write, or should I simply be reusing them?  A single run of my software runs for 12-14 hrs and the exception is only thrown every 3-4 runs.

Here is a stripped-down version of the programs my DoWork event

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)

{
 const bool RETRACT = false;
 const bool INSERT = true;

 var jobSettings = e.Argument as JobSettings;

 DigitalSingleChannelWriter writer = null;
 Task digitalOutputTask = null; 
 
 for (int i = 0; i < jobSettings.TotalCycles; i++) {

   mBusy.WaitOne();
   if (worker.CancellationPending) {
      e.Cancel = true;
      return;
   }

   try {
    digitalOutputTask = new Task();
    digitalOutputTask.DOChannels.CreateChannel($"{jobSettings.NIDevName}/port1/line3","DigitalOutput",ChannelLineGrouping.OneChannelForEachLine);

    writer = new DigitalSingleChannelWriter(digitalOutputTask.Stream);
    writer?.WriteSingleSampleSingleLine(true, RETRACT);
   }
   catch(Exception ex){
      System.Diagnostics.Debug.WriteLine("Exception occured WHEN trying to Rectract: " + ex.Message);
      throw;
   }

   finally {
      digitalOutputTask.Dispose();
      digitalOutputTask = null;
   }

   //report status & worker progress

   //wait x seconds
   Thread.Sleep(Convert.ToInt32(jobSettings.SecondsToRetract * 1000));

   //report status & worker progress

   try {
      digitalOutputTask = new Task();
      digitalOutputTask.DOChannels.CreateChannel($"{jobSettings.NIDevName}/port1/line3","DigitalOutput",ChannelLineGrouping.OneChannelForEachLine);

      writer = new DigitalSingleChannelWriter(digitalOutputTask.Stream);
      writer?.WriteSingleSampleSingleLine(true, INSERT);
   }
   catch(Exception ex){
      System.Diagnostics.Debug.WriteLine("Exception occured WHEN trying to INSERT: " + ex.Message);
      throw;
   }
   finally {
      digitalOutputTask.Dispose();
      digitalOutputTask = null;
   }

   //report status & worker progress

   if (worker.CancellationPending) {
      e.Cancel = true;
      return;
   }

   //wait x seconds to insert
   Thread.Sleep(Convert.ToInt32(jobSettings.SecondsToInsert * 1000));

    //report status & worker progress

 } //for loop

} //DoWork event