Hi JL,
It is always helpful if you are able to submit a small amount of code that reproduces the issue you are seeing. The size of your code makes it very difficult to narrow down what could be causing your issue. In addition to the size, I noticed a few items that could help improve the readability of the code, as well as improving efficiency in run-time and in troubleshooting. I have listed them below and included screenshots to help explain as well. It also seemed to me like you may be trying to implement state machine architecture, so I have included a White Paper below as well.
In regards to the original question, it is possible that the value is being maintained in an uninitialized shift register. I would recommend using default values to initialize the shift registers of the While Loop. I hope you find this helpful!
1) Clusters- It may be helpful to pass data from one loop iteration to another through a cluster. When we want data from it, we can use the unbundle functions. See “Before Cluster” and “After Cluster”
2) Array versus Matrix Functions- Although Arrays and Matrices are similar, they are not exactly the same. See “ArrayVsMatrix”
3) You can branch wires from a constant- see “Const”
4) You may want to check your code for unneeded logic- See “Equivalent Logic”
5) It is possible to expand property nodes- see “ExpandPropNode”
6) SubVIs-I noticed that there were several areas where there was repeated logic. Making a SubVI would make it easier for maintenance. See “Repeated Logic”
State Machine: https://www.ni.com/en/support/documentation/supplemental/16/simple-state-machine-template-documentat...
Regards,
Jason D
Applications Engineer
National Instruments
