Shared Variables stop working on cRIO-9074

[Dave_Thomson]

   I have a Dell E5540 laptop running W7 and LV 2013.  The project talks to a cRIO-9074.  I use a handful of shared variables to communicate some of the data between the two platforms.  I have gotten this all working fine.  Then twice, something has gone wrong.  The shared variables just stop communicating.  They are hosted on the laptop.  The host program sets them just fine.  The Distributed System Manager can monitor them and sees them change.  But the RT program never gets the new values.  The RT connection is fine.  I can probe into the running RT VI, and I see that the shared variables do not get the correct values.

    The firewall is off.  I've undeployed and redeployed everything over and over.  Cycled power, rebooted, etc.

    In both cases, I finally was able to fix the issue by re-installing the entire suite of NI software on the cRIO.  After I did that, the program started up and behaved fine.  I have no idea what triggered the failure in either case.  Also, I have a second laptop that I've used to verify that the problem is with the cRIO and not with the laptop.  When things are broken, it fails with both laptops.   As soon as I reinstall the software on the cRIO, both laptops work with it fine.

    Has anyone seen this before?  Any ideas how the cRIO might be failing?  It seems like some software component on the cRIO must be getting corrupted, since the software reinstall is the only thing that fixes this.  Perhaps the cRIO is bad?  The one other possible clue I have is that during the second fix, I even went so far as to reformat the cRIO disk using MAX.  After the format worked for a while, it popped up an error saying that the format had failed.  But I was able to reconnect and reinstall the software and get things running.  I just wonder if that error code is another symptom of a bad piece of hardware...

Thanks,

    DaveT

[sassyaspy]

Hello Dave,

You can try to pinpoint where the problem is with some tests. First, you could try running the real-time VI on your host instead and seeing if the problem with communication still occurs. Then if this seems to work fine, try running a LabVIEW shipping example for network shared variables on the host and target. One such example is Analog Input - Getting Started - Scan Mode.lvproj from the NI RIO driver.  If this succeeds, the problem is most likely with the LabVIEW application you have. However, if it fails there is a much higher chance that there is a problem with the cRIO.

Have a good day,