Systematic errors for Labview Run-time Engine (lvrt.dll)

[Eric Desfonds]

Hello all,

Thank you in advance for any help provided.

I am currently developing an application in Labview 6.0.2, which communicates through a DAQ card to an optical detector rack.

All calls to the detector rack are done through the provided DLLs. All calls were tested as individual building blocks and the application runs perfectly when running within the Labview development system.

Problems occur when this application is built using the Application Builder and ran using the 6.0.2 version of the LabView Run-time Engine. The Application has very large arrays (16000 double-precision numbers) and they have to be referenced to by Local Variables to be passed from one part of a sequence of events to anoth
er.

Invalid Page Faults in LVRT.DLL are coming up, systematically at
017f:30206364 (most of the time)
017f:30205d0A (sometimes)
017f:30205f86 (sometimes)
017f:30203f93 (sometimes)

All necessary DLLs are included in the Build Script, and copied to the Executable's folder. The application does run for a while, but when a call to the DAQ card occurs, these errors come up.

The application was originally developed on a Windows 2000 machine, but compiled both on the Windows 2000 and on the Windows 98 computer meant to operate the system. No difference were seen.

Any ideas how I can interpret the LVRT.DLL errors or invalid page faults would be appreciated. It seems that memory management is the issue, but your past experience may be invaluable to me.

Cheers, and have a nice day!

Eric Desfonds

[Aaron Marks]

Are you calling the driver DLL's directly from LabVIEW, or are you calling them from your own external code modual. If calling the DLL directly, make sure you are handling errors from each function call. I have seen some problems where pointers are obtained in one function and passed to another, but if a failure occurs, null pointers get passed and cause problems. You would have to check for such things in LabVIEW. If calling the DLL from your own code, make sure you are handling all the errors there. Remember, DLL functions are often themselves calling other dll's and you may run into runtime linking problems if things aren't exported properly. Errors which occur in external code modules are outside of LabVIEW's control and quite often can cause errors
in the lvrt.dll.