Random crashes talking to dll

Question

I have a vi where I am talking to a dll. This vi will crash LabVIEW at random intervals, usually after I have run the app a number of times and then close out the vi. Can someone with more experience with dlls look at this and let me know where I am not working this right? I have found out the hard way that the timers are required where they are.
This dll access some hardware, so I don't expect you to be able to have it run, but maybe somwhere I have the function calls incorrect. The hardware is a Silicon Labs CP2102 USB to UART Bridge Controller chip.
Files attached, including the dll documentation.
NOTE: you will have to change the "CP210xManufacturing.txt" extension back to "dll". I can't post a dll extension to the forum.
Thanks!
Tay
Attachments:
CP210xManufacturing.txt ‏88 KB
an1441.pdf ‏364 KB
GetPartNumber1.vi ‏23 KB

Answer 1

The documentation has for that function:
Return Value: CP210x_STATUS = CP210x_SUCCESS, 
                                                        CP210x_INVALID_PARAMETER,
                                                        CP210x_INVALID_HANDLE,
                                                        CP210x_DEVICE_IO_FAILED
In Appendix A, CP210x_STATUS is defined:
// Type definitions
typedef int CP210x_STATUS;
Thus, the return value is an integer (I32 in LabVIEW).
A "1-byte" value is just a U8/I8 in LabVIEW. Note that this function requires you to pass a pointer to the value. You should wire a constant to that node:
Attachments:
GetPartNumber1-1_BD.png ‏2 KB