Shared Variable Read Error 1950679035

[wynnc]

I have a LabView 8.5 real-time program running on a FieldPoint cFP-2120 processor which communicates to a LabView 8.5 program running on my PC over a dedicated ethernet line.  After two days of continuous running I get an error message for several of my boolean shared variables..

Error-1950679035 occurred at shared Variable Read in HB.lvlib:HotBake_TopLevelHost.vi. 

Possible reason(s):

LabVIEW:  Unable to locate variable in the Shared Variable Engine.  Deployment of this variable may have failed. 

This warning occurred while reading \\HB\HotbakeVariables\LoopActiveA (\\10.10.10.2\HotBakeVariables\LoopActiveA)

I don't understand why it would work fine for two days and then have this error occur.  Any thoughts?

Thanks, Wynn

[eek]

Hi Wynn,

Do you have a firewall installed on your host computer? If so, it might be the culprit to this issue. Disabling the Windows Firewall temporarily would be a quick fix. If you want to keep the firewall enabled, follow these steps to unblock NI's Shared Variable/Tag software.

In general, your error indicates that the read or write could not be completed because the variable could not be found in the Shared Variable Engine. It typically occurs if the library containing the variable was just deployed and the read or write operation took place before the variable became available in the system. Thus, when your VI first starts up you can ignore this error.

[wynnc]

Thanks for your response Emilie.  I checked my firewall and found that my firewall was OFF.  You got me thinking however.  This problem has happened twice to me and both times they were in the middle of the night around midnight.  I have a dedicated ethernet line between the FieldPoint and the PC (it is not connected to the network).  I do however have another network card in a PCI slot so I can get on the internet when necessary.  I am wondering if there is some sort of corporate maintenance activity going on periodically at night that might interfere with the operation.  I think I will unplug the external network connection and let it run for three or four days to see if I get the error message again. 

There were six 1950679035 error messages received for each of six shared variables.  All of these get read or written to on each cycle of my control loop.  Since it ran from Friday night until Sunday night with no problem I don't think the problem was "1) The shared variable was undeployed".  After I acknowledged the six error messages, things continued as normal so I don't think it was "2) The shared variable engine is no longer running".  But, if some other program of higher priority is run such that the shared variable engine doesn't have enough time to respond, do you think that would give me the ...79035 error?

Just a thought.  I am grasping for ideas.  Anyway, I will disconnect the outside network connection and see what happens.

Thanks, Wynn

[eek]

Hi Wynn,

I like where you're going with this. If there is some sort of routine network maintence, it may be disabling Shared Variable Engine. Thus, I think disconnecting your computer from the network is a good troubleshooting idea. If anything, it will help reduce the number of culprits to this issue.

I look forward to hearing from you with the outcome.

Until then,

Emilie K. | Applications Engineer | National Instruments

[Conejo55]

I got problems using MyRio with shared variables, I could read but not write shared variables to myRIO, so I followed the spteps on this link and nothing changed, so I found that only disabling my Internet connection I could write SV to myRIO, is there a way to do that without disabling my Internet connection? Thaks a lot!!

Regards

[Agamemone]

Hi Conejo55,

The original post is under the FieldPoint Family category.You should post this as a new thread in the Academic Hardware Products section that describes your situation better so that more people who are better versed with myRIO and shared variables will see it.

In the meantime, here is some background information on shared variables:
http://www.ni.com/white-paper/4679/en/