You can use the Open Trace VI to create a direct trace for writing to a Citadel historical database. Complete the following steps to open a trace for writing:

  1. Add the Open Trace VI on the block diagram.
  2. Wire the URL of the Citadel database to the database URL input of this VI.
  3. Choose a name for the process and wire it to the process name input of this VI. Use the process name input to define a logical grouping of traces.
  4. Choose a name for the trace and wire it to the trace name input of this VI.
    Use the name of an existing trace to append data to the end of that trace because the Open Trace VI fails if there is an open trace refnum for the trace already. This VI also fails if the Shared Variable Engine is writing data to the trace already.
  5. Use the polymorphic VI selector to choose the type of the data you want to write.
  6. Optional: Configure the timeout and precision of the trace.