I have trouble with Shared Variable Engine (SVE) on Linux Real-Time CompactRIO 9053.
I noticed problems when startup application operates with Shared variables soon after boot. It then takes exactly 5000 ms to write/read the SV, which makes enormous problems when in time critical loops. It obviously happens only when reading/writing the variable for the first time.
And now the cool stuff: the problem emerges only when there is no Internet connection. When the unit is either disconnected from router or connected to PC via Link Local or connected to router disconnected from the internet, working with shared variables takes 5000 ms. When it is connected to the Internet, target works as expected. It is very hard to debug because few seconds after the boot the problems disappear - I have no problems when running through LabVIEW because I think it is too long after startup. If we find that SVE communicates with an external server natively, it makes SVE undesirable in our app for security reasons.
I've made a minimal working example. Target needs to have Shared Variables installed. Build the app and run it as startup. When you disconnect cRIO from the internet and power it up, the LED shines for 10000 ms and then starts blinking. When connected to the internet and powered up, blinking starts immediately, with very small delay.
I need to get rid of these delays so I can rely on this communication taking no time.
I wrote a service ticket to NI.
