RT FIFO delete in one loop does not generate error in other loop reading the fif

[Andy josh]

I have been using the RTFIFO in my app. in LV 6.1 and I was using the error, obtained from reading a deleted FIFO to stop my parallel running while loops. I have noticed that this feature is not available in LV 7.0. The RTFIFO just displays it as a warning. Is this true?

[Carl L.]

Andy,
I tested your VI and got errors after the RT FIFO Delete ran. I tried it both in Windows and on an RT target. I did get different errors in the two cases, which is inconsistent. I'll report that. In RT I got the error -1 and in Windows -2206.
One thing that I noticed as I loaded the VI was that it was looking for RT FIFO VIs in the llb HRCtest.llb. Since RT FIFOs are VIs that ship with LabVIEW Real-Time you should be using the once in the original location (vi.lib/addons/rt/RT FIFO.llb). If you want to make changes to it then you should save it under a new name first. The easiest way to point it back to the correct VI is to rename the VI in the HRCtest.llb, then next time LabVIEW loads your VI it will search for the RT FIFO VIs and find them in the vi
.lib folder.

Carl L
National Instruments

[Andy josh]

Carl,

Even after correcting the VI linking and making sure that all the RTFIFO's are from LV7.0 vi.lib the slave loop under the PXI targeted mode does not stops. In windows I do get the error 2206 but under RT I get the warning with code 2.

[Carl L.]

Andy,
I can't explain this. I have tried it on several different RT targets here and from several machines. All of them give an error of -1 in RT. The only differnce now is that you are loading the nbfifo.dll from National Instruments\shared\system, and mine gets loaded from vi.lib\addons\rt. However I tested by redirecting it to the other copy and it made no change. It still gives an error of -1 when the fifo was deleted.

Is there anybody else that gets a warning code 2 in RT?

My suggestion is to rewrite the VI to look for a non zero error code.

Carl L
National Instruments

[Andy josh]

Carl,

Thanks for mentioning the nbfifo.dll. I think I was using the old nbfifo.dll obtained on NI FTP server prior to LV7.0. I replaced the dll with the the one from lv7\addons\rt and i was able to reproduce the error.
How do we check which dll is being used? Is there any hierarchy info that can reveal this information?