Shared variable not working properly, LV 2009, real-time module PXI

[Steve76]

Hello-

I have a complex program developed under Labview 8.6, running on a real-time PXI system. I am duplicating the entire system, and recently bought a newer PXI. Because the new PXI had the Labview 9.0 Real Time module, I had to put Labview 2009 on the new host system.

For the most part, the code runs fine. However, I am having a problem that I think I have traced to a shared variable (single process, Int16). The shared variable is updated inside some nested loops. I can verify that the variable does in fact update within the loop. However, when the loop cycles back through, the variable still has its previous value, it does not retain the new value.

I am fairly certain that this is not an algorithmic problem, as I said I have the IDENTICAL code running just fine on another system, with lots of miles on it, and have never seen this.

I notice that NI tinkered with the shared variables for LV 2009. Is it possible that there is a version glitch that is causing this problem?

Thanks,
Steve

[Smootastic]

Hi Steve,

When you say it still updates, do you mean that you see the new value later than anticipated?  Does the shared variable have a Real-Time FIFO enabled?  Are you seeing any errors or warnings out of the shared variable read?

Are you able to simplify the code to a VI that reproduces this issue?  You can attach it to this post.