-1950679035 SVE problem

[ahmalk71]

Hi!

One of our costumer is facing a new issue with an application that we have delivered. Unfortunately I can't attach the code since it is classified as secret. Any how I'll try to explain the best I can. The system consist of 1 Windows PXI and 2 RT PXI controllers. The SVE is installed at the Windows machine and is used only for communication purpose (one variable only). I have also checked for deploying the SV on application start. The two RT systems starts with a series of initiation VIs before entering the main VI. The first VI in the initiation series uses "open and verify variable connection" inside a while loop with timeout set to -1 and the condition for while loop is set to continue if true. If any errors occurs in the rest of the initiation process the Main VI is never reached, the application restarts and the error is logged. Inside the main VI there is a MHL that use a "read variable with time out" to check for new available data. Now lets talk about the problem. This problem occurs every time the application starts for the first time after the system have shutdown for a while, restarting the application the problem is gone. The error we get is -1950679035 that occurs in the "read variable with time out" inside the MHL. I hardly believe that this is caused by failure in the SVE deployment, since we have gone through all the initiation, without error, including the first initiation which is "open and verify variable connection". I don't think a busy SVE is an issue either since the only command that i send from the windows machine is "START". I will visit the customer in two weeks time and appreciate all input I can get to prepare my self.       

Best regards

Ahmed

[AshleyNunn]

Hey Ahmed,

There is an overflow fo documentation for this error, which can make it hard to find the document most suited to you.

The most comprehensive seems to be: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000PAinSAG&l=en-GB

From your description, the areas I would focus on are:

1. CPU. Are you abe to measure the CPU resource usage on the RT PXIs? If the CPU usage is high, are the lower priority loops (like SVE) being starved? Are the variables hosted on the RT or Windows PXI?

2. Does this error "-1950679035" Occur once and then the application stops or does it occur continuously for many seconds? This error can occur if you try to read too quickly from when everything has been deployed/setup. A simple step is adding a few seconds of wait before you get to the loop that does the read. you can play with the wait time, try something super high like 30 seconds just to see if there is an impact (even if it may be unacceptable as a finished state).

Normally, this error is safe to ignore at the start of an application

-Ash

[ahmalk71]

Hi Ashley!

Yes, I'm using a display on the RT systems and CPU usage is at most 30%. In each target I have a producer and a consumer loop, in addition to that I have MHL consisting of de-queue and a SV read node. The dequeue is used for internal message handling while the SV read node is used for external message handling. Both node have the time out set to 1 ms. if the dequeue element is not timed out the data enter a false case to handle the data, while if timed out it enters the true case to check the SV read node which in turn uses its time out output to enter another case structure.  The SVE is hosted by the Widows PXI. I found it as most convenience way to host the SVE.

The error occurs once every time the application starts for the first time after the systems have been shutdown. Once the application restart the problem despair. The first time the read node is used is after the initiation procedure. I could always add a wait function before entering the main VI to be sure that everything have been settled down. However if the initiation starts with the open and verify connection vi doesn't that mean that the deployment in the Windows PXI is already finished?

Thank you very much for your help

Best regards

Ahmed