I'm using LabVIEW to develop a DSP (Digital Signal Processing) application, when upgrading my code from LabVIEW8.2.1 to LabVIEW8.6.0, some functions working properly in LabVIEW8.2.1 now give incorrect result after being upgraded to LabVIEW8.6.0. After debugging, I found that the feedback node in LabVIEW8.6.0 introduces abnormal Data Type Conversion, I solved it by replace the feedback node with a shift register, is this a bug?
Here I attach screen shots of one of my VIs, in this VI I'm using feedback node to implement point-by-point digital filtering on input complex data, attached file"Code_LV82.PNG" shows its diagram in LabVIEW8.2.1, if I open the same VI in LabVIEW8.6.0, the initial terminal of feedback node is now visible and there are 2 extra auto Data Type Conversion (shown as red dots) at output branches of feedback node (in attached file "Code_LV86_Marked.PNG", refer to where the 2 blue arrows point to), and this VI functions improperly. In LabVIEW8.6.0 if I replace the feedback node with a shift register or give a constant "0+0i" to the initial terminal of feedback node, the 2 extra auto Data Type Conversion are gone and everything is ok.
Here I also attach my VI (as attached "wt_2nd Order Low Pass Filter.vi " ), you can try if my problem could be replicated.
Any suggestion is welcome, thanks in advance.
