PLeVasseur

D'oh! Thanks for pointing that out, ShaunR. I'll have to keep a lookout for this in the future. Is there rationale that was given from NI for why this (or any other) property is not available?

Some background: I'm trying to use the name of the library my VI is executing in as part of a string which will be used in the name of a Rendezvous, to keep it distinct from other Rendezvous I will create. When attempting to use the VI Property Node to access the Library property on the CompactRIO, error code 1 is returned. Running the same code on my computer runs as expected and returns the Library. Accessing the VI Name using the Property Node appears to work no problem on the RT, though. Does anyone know what could be causing the problem? I tried searching the documentation, but didn't turn up anything. Is this error part of some general behavior wherein some VI properties are not accessible when a VI is running on a real-time target? Code is attached. Please see attached pictures: Project Explorer: Block Diagram: Front Panel - RT Results: Front Panel - Computer Results: Experiment with VI Property Node Error.zip

Well, after working at it for a while longer, in the end I couldn't get programmatic access to shared variables to work on the CompactRIO. I spent some time reworking the code to function with Network Streams and I'm pretty happy with the result (since it works!). Thanks Neil.

I appreciate the suggestions, JKSH. Answering your questions in order: What happens if you delete the SV node from your block diagram? Same error code (-1950678943). What happens if you try to write to the variable without opening a connection? Same error code (-1950678943). Right-click the SV node and select "Replace with Programmatic Access". Does this one work? I tried this previously, but it didn't work out. Same error code (-1950678943). What happens if you undeploy everything from your cRIO, and then deploy the variables again? Tried this previously, too. I tried undeploying and then deploying again, but same error code. What happens if you undeploy everything from your cRIO, and then create a new project with new variables? Nope, same error code. Verified that all shared variables were not deployed prior to creating the new project by using the Distributed Systems Manager. (Drastic measures) What happens if you reformat your cRIO, install your software from scratch, and try again? Just tried this too, unfortunately no success. The situation remains as follows Computer: Shared Variable Node - Success Programmatic Access - Success cRIO: Shared Variable Node - Success Programmatic Access - Failure (Error Code -1950678943, Error message: "Timed out while attempting to open a connection to the variable.")

Thanks for the suggestion Neil. I tried doing this previously by first turning a shared variable node into the Target Relative mode, then replacing with programmatic access, which resulted in a URL like you mentioned (ni.var.psp://localhost/...). I still received the same error code (-1950678943). I am open to other ideas as to how to accomplish sharing data between the computer and the cRIO. Do you have some tips you could share? It seemed that shared variables would be an easy way to do that, but I can't seem to get programmatic access to them to work from the cRIO (though access via shared variable nodes works fine).

I would like to use programmatic access to manipulate shared variables on a computer and an NI cRIO 9033, but cannot get programmatic access to shared variables on the cRIO. I have boiled the situation down to a simple example to try to explain what I am seeing. The shared variables are hosted on the cRIO. I am using the same VI to perform the accesses on the computer and the cRIO. On the computer, access to the shared variable via a shared variable node and programmatic access both work. On the cRIO, access to the shared variable via a shared variable node is functional, but programmatic access to the shared variable does not work. The error code received when trying to to a Read Variable or Open Variable Connection on the cRIO to the shared variable is -1950678943. The error text reads "Timed out while attempting to open a connection to the variable." I'm quickly becoming confused as to why the cRIO should have trouble reading a shared variable programmatically that is hosted on itself. The web searches I have done haven't turned up such a simple scenario causing this error, so I'm wondering if I've stumbled into a beginner mistake. I have attached the source code to this post, so if someone could please take a look that would really help! Block Diagram: Result of running on computer (programmatic and shared variable node access both work): Result of running on NI cRIO 9033 (programmatic shared variable access does not work, shared variable node access does work): Test Access to Shared Variable from cRIO.zip