回复： myrio loses connection on excution of a complicated formula node

[张弋]

I use a formula node to excute some annoying code on myRio linux RT, but everytime I run the VI containing the formula

node it pops a warning immediately after compilation : Connection to the target (myRio) has been lost.

Afterwards, I try to write the formula in C code and wrap it as a shared object (.so) and deploy it on the linux RT. The wierd

thing is that  the warning continues to show up everytime I call the shared library using a Call Library Function Code.

Finally, I rewrite the code using Mathscript RT Node, it works although very slow and it does'nt achieve my performance requirement.

Also, I comfirm that the same formula node works just fine in PC enviromment.

After some searching, I think it may be because of the too many variables declared in the function, which use up the

allocated memory  or CPU time.  But I think it should not have been the case when I call a function from shared library 

[张弋]

BTW, here is my formula node code which has numerous local variables.

and here is what the warning is like

[张弋]

BTW, here is my formula node code which has numerous local variables.

and here is what the warning is like

[张弋]

BTW, here is my formula node code which has numerous local variables.

and here is what the warning is like

[Spux]

Hello. I have the same problem. Did you find any solutions?

[张弋]

Not yet, so sorry

[Spux]

Okay. I will try it with Mathscript RT Module. The other idea that i have is to use Shared Library on myRio...

[张弋]

Unfortunately, The shared library has the same problem as the formula node, as I found out. But MathScript module works just fine.

[mikeporter]

It doesn't look like the myRIO doesn't have enough horsepower to do your flight-control calculations and maintain connection at the same time.

Mike...

[dkfire]

Remember that the myRIO is a embedded controller, that should be able to run standalone.
The program runing on the myRIO should not/will not have a front panel.

When you run the vi on the myRIO from the project explorer, the front panel is not really runing on the myRIO, only the code.

But LabVIEW needs to transfer data to and from the front panel to the myRIO.
This takes extra recourses on the myRIO, and LabVIEW need the link to be able to transfer the data.

The communication to the front panel on the PC has the lowest priority on the myRIO. If you are using all the recourses for the code, this communication will not happen. If the communication is paused by the myRIO, you will get this warning.

You need to make your own communication between the myRIO program and the PC if you want data from the myRIO on the PC or send commands/actions to the myRIO.

Go through this to get a idea of how myRIO is working:

http://www.ni.com/compactriodevguide/