Error 1031 with VI Server

[jshafer]

Hello,

I am working on a project that uses a VI Server to control a piece of hardware persistently across multiple DLL calls. I have several remote calls that simply grab the main server reference and call a remote version of a function.

This works for about half of the functions, the other half are returning error 1031. All the remote functions are similar Open Application Reference->lookup full class name of remote VI from exported functions->Open application reference with an input type that is the remote function panel->call by reference->close.

This is all within a class on LV2012 and running on windows XP sp2. It was developed in Windows 7 LV2012 and seemed to be behaving there, but the hardware wasn't available for a full test.

Thanks,

/r

James

[mikeporter]

The error means that the VI Reference type does not match the VI connector pane. Is that the case?

Mike...

[jshafer]

If it is, then something is changing it when it is loaded into memory. Is there any way to determine this?

When I call Open VI Reference I have created the type specifier VI refnum from the VI I am calling with that function.

/r

James

[mikeporter]

Are you sure nothing has changed?

Mike...

[jshafer · Accepted solution]

Correct nothing changed. Though I did discover that the error did exist in Windows 7 just not in the functions I was using to test.

I managed to resolve my problem. It turns out that when I was pulling the full VI name from the Exported VI list, all the failing VIs were being pulled with :Instance.0 attached to them. The solution was to ensure that I was just calling className.lvclass:viName.vi without the Instance qualifier.

Thanks

/r

James

[mikeporter]

Good thing to know. Where did the ":Instance.0" string come from? Were the VIs reentrant or something?

Mike...

[jshafer]

I believe that to be the case. For every instance where an exported VI was called as a subVI of another exported VI (advanced functions to increase speed would combine the simpler functions for a call fully on the server before returning results).

Since I would match the string of the VI name (minus class), without the necessary class qualifier, that was the first match returned from searching of Exported VIs which I was using to get the full name for the open reference.

Hopefully this saves someone else from the same frustration.

/r

James