LabVIEW
invalid access to memory location
eellenoff wrote:
Hello, I'm relatively new to LabVIEW, and I'm stuck on a problem that I just can't make sense out of. I wrote some vi's on a development computer that make use of a DLL written as a device driver by ocean optics. I got everything more-or-less working on the development machine, and then went to move my application to the machine where it would be used. Now, when I try to open up any vi which calls the DLL I get "Invalid access to memory location". I've tried reinstalling the software that creates the DLL, I've tried cleaning out the registry, and I've made sure that my vi's still work on the development machine. I've even tried re-copying the DLL directly from the dev machine. I'm at a total loss and would appreciate any help you can offer. Thanks,
-Eric
I had the same problems and they suggested the following fix that worked for me!
Goto Start -> Run -> type "ooidrv.ini" (without the quotes). This will bring up the .ini file for your oceanoptics device.
Make sure that "Initialized=1". Mine was set to 0 and changing it to a 1 made all of the "invalid access to memory location" errors go bye-bye! 
@gedvell wrote:
Hi,
I get exactly the same error when I try to run the LV_sql VI's that interfaces labview with the MySQL database (downloaded from http://sourceforge.net/projects/sql-lv/).
On one machine running XP and LV8.2, I get the Invalid access to memory location error when the DLL in the aplication is being loaded by the Call Library function. I also tried labview 6.1 on this machine but get the same error.
On another machine also running XP but LV 6.1 I don't get this error when I'm droping a Call library function in a new VI and select the same DLL.
Cheers
Goran
Of course the DLL could be doing something illegal internally. But one very likely problem for such errors, or other strange errors such as LabVIEW crashing at some point after having called a DLL function, is usually that the DLL configuration passes wrong dataypes to the DLL or in the case of output buffers a way to small buffer than what the DLL wants to write data into.
In all cases it is not really a LabVIEW problem. If you can use a DLL in other applications without ever having problems you are most likely running into the problem of wrongly configured parameters or to small buffers passed into the DLL. Otherwise chances are of course the DLL itself does not cope with certain situations properly.
LabVIEW itself crashing on DLLs out of its own fault is in fact very unlikely since quite some versions. It's really something like 99.9999% of the cases a problem in the DLL Node configuration or with the DLL itself. And the nasty thing is that if you pass in to short buffers for instance it mmight just as well seem to work for a long time without trouble and suddenly some seemingly small changes make it all crash consistenly or if you are unlucky also randomly.
Rolf Kalbermatter
