Howdy do.
While incrementally developing and testing an application on a crio9068 (linux RT) I've begun to see the 'finished late?' indicator in my main timed loop flicker. Starting to pull my hair out trying to figure out how to prevent this from happening. I made a 'hold max' vi and can see the longest execution time for each frame.
The application runs fine at about 75% processor load with the front panel open, and the majority of iterations execute in time. Occasionally, I'll have a 'spike' in execution time, and all four frames in the timed loop take significantly longer than normal to execute, and the 'late' indicator says so.
A couple questions I've had build up while chasing this:
-If I use local varables to pass data between loops, but only write to the variable in one place, can I still cause a blocking condition/jitter by competing reads of that memory space?
-If I use an FPGA read/write node to pass data between the timed loop and the FPGA, should I expect this to cause a problem? I selectively disabled a lot of my code, and it seems like this is where some of the delay occurs. What stumps me is that these parts of the code haven't changed in recent development and the thing never used to run late.
-On the topic of the FPGA read/write node, I previously assumed that I shouldn't write to the same FPGA FP item in different subvis. However, the code is set up so that there are multiple parallel calls to the read/write node, just with different elements selected. Is this BAD?
-Similarly, if I unbundle and read the same element from a cluster control in a 'parallel' fashion, can this cause a blocking situation, or is it the same as unbundling and wiring from there to multple places?
-I am using the recently renamed "NI software calibration and management toolkit (SCM)," formerly Drivven CalView, to handle communication between the RT and a windows host. It also does neat fault management stuff. Anybody else using this, and is there any possibility I'm getting jitter by having too many calpoints in my deterministic loop?
Any guidance on any of the above points would be greatly appreciated. If I don't make sense on any of the above points I can make example snippets to describe.