Undirected Tunnel Error With Stacked Sequence Structure

Updated May 20, 2024

Reported In

Software

  • LabVIEW Base
  • LabVIEW Full
  • LabVIEW Professional

Issue Details

When I run my code, I receive an  Undirected Tunnel Error. LabVIEW identifies a stacked sequence structure on my block diagram as the source of the error. How do I fix this error?
 

Solution

There are a few different steps you can try to fix this error:
  • If a source is connected on both sides of the structure or no source is connected, the tunnel cannot decide the direction of dataflow. Verify that every case in your stacked sequence structure is fully wired, and that a source is never connected on both side of the structure. The LabVIEW Help has more detailed information on this case. 
  • Remove any broken wires in your VI by selecting Edit»Remove Broken Wires or by pressing <Ctrl-B>
  • If you have tried both of the previous steps and are still seeing this error, try replacing your stacked sequence structure with a flat sequence structure. Right-click the stacked sequence structure and select Replace»Replace with Flat Sequence to resolve the error.

Additional Information

A tunnel serves as either an input or an output from a structure. If a source is connected on both sides of the structure or no source is connected, the tunnel cannot decide the direction of dataflow.

Related Links

LabVIEW Help: Wire connected to an undirected tunnel

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