Network shared variable w/rt fifo reads cross coupled values (LV2009)

[viScience]

I have a cRIO with a library of NSV's that are used as read only constants.  In order to speed

up the access time I enabled the RT FIFO option which helps quite a bit.  Unfortunately after I did

this I have experienced a variety of strange behaviour one of which is a cross coupling between variables.

I do not see it in the Distributed System Manager but can see it if I proble the diagram.  It is not a simple

cross coupling but rather what I saw was a toggling of the correct constant number A and B-A where B is some

other variable in the library.   I noticed an earlier post concerning a related RT FIFO problem reported in LV 8.6.

[Smootastic]

Hi sachsm,

I'm confused with your application.  Are you using the NSVs to broadcast these constants to clients?  If the values remain the same, why is an RT FIFO used?  You could try creating a cluster NSV (you'll select custom control) to hold your constants, or since the values stay the same you should only need to read once and then use a shift register on the client to hold the variables. 

Perhaps a screenshot or VI could help clarify things. 

[viScience]

The NSV's in question are used as system parameters whose values are deployed to the rt target via a FTP XML definition file.

The XML files can be downloaded on the fly and the rt target signaled to load the new values to the NSV library.  In my experimentation

I discovered that NSV's with the RT FIFO enabled can be read by LVRT much faster than a NSV without the RT FIFO enabled.   Unfortunately,

as I originally mentioned, it has some strange side effects.  I like using NSV's since they can also be viewed and changed via the distributed system manager.

[Smootastic]

Hi sachsm,

Let's make sure that this occurs in other instances outside of your application.  If you test this issue with a smaller VI, can you replicate it?  You can attach it to the post so that we can verify it at NI.