data acquisition with DATAQ DI-700 via activex

[Dnalor]

I am developing under Labview 7.0 a data acquisition program which reads voltages from the USB-DAQ-device DI-700 (from company Dataq http://www.dataq.com/). The communication is done via ActiveX. On my computer (Win XP) where the LabView Development Environment is installed everything is working perfect. Even when I build an executable for the Labview 7.0 run time engine it is still working on this computer.

If I install the executable together with the Labview 7.0 run time engine on other computers (Win 2000 or Win 98) the activex invoke node, which calls the data acquisition routine, returns always "Unknown system error code 97" (oleNullRefnumPassed) and no data are read from the DI-700. However, the actual system drive
rs of the DI-700 seem to be correctly installed, because the data acquisition software from Dataq is working on all these computers without problems.

It is the first time that I am doing ActiveX programming in Labview, so I might make a stupid mistake. But at the moment I have no idea how I can encircle the error source. Does anybody have some suggestions?

[Jeremy Braden]

This is a strange problem. I think what you need to do is isolate the node that is producing the error. The idea is to open the bad subVI and put several error indicators on the front panel and connect them in critical points in your code. This way you can look at the front panel of the executable and see where the error occured.

Now you have to make the executable show the bad subVIs panel when it runs. First goto the VI property page of the bad subVI >> Window Appearance >> customize >> show front panel when called. Now when the main VI calls the subVI, the bad subVI's front panel will open. The next step is to edit how you build the main VI. In application builder go to the VI settings tab. Click on the bad subVI and choose to edit build settings.
Make sure the front panel is left on the subVI . Your executable should now be cooking for isolating the problem.

Good luck.