Intermittent, Partial Network Shared Variable Communication Issue

[Andy__S]

Hi all - I have a strange issue with my RT System (NI 31xx series industrial controller paired with a NI 9157 running 2010 V10.0f2) which is being used to test a battery, related to NSVs. Right now, I'm running in development mode so I can interact with the RT VI as well as the HMI on my host computer. At a certain point during operation (initiating charging of the battery), the HMI loses partial contact with the NSVs. Yesterday the NSVs which issues commands to the RT system (writing to the NSVs on the HMI and reading them on the RT system) was not updating on the RT system and today it's the variables which provide system data to the HMI (writing on the RT and reading on the HMI). When the error occurs, the unaffected NSV continue to update as expected. It seems like the variable traffic suddenly becomes one-way only. The strange thing is that the error starts right when the battery begins to charge. Discharging the battery does not cause the error to occur even through the both program routines are identical except for the value of the power command to instrument which regulates the power flow and a few other variables related to the state machine.

Further, the error is not consistent. It does not occur every time a charge is started. Once the error occurs, the only way to re-establish communication is to restart the VI on the RT. This brings the NSV communication back to normal until the charge is started again, then the same error occurs. If I go ahead and cycle the power on the RT system, the problem seems to go way for a while (i.e.. I can charge without problems).

I am in the process of getting the software up to date (corporate hoops to jump through...) so hopefully that fixes the issue. Any other suggestions on how to diagnose or fix the problem are appreciated.

Thanks.

[Andy__S]

Update: Loss of variable communication (still just one-way or the other) still occurs but appears to be more random (not just associated with a specific action such as charge initiation).