From the page: http://www.ni.com/tutorial/14690/en/
Once you have logged in, expand the files under your embedded system to find /usr/local/lib. Now, expand the files under your local computer to find your .so file. Drag it from the host computer to /usr/local/lib to transfer it to the embedded system.
I performed the above on a simple calculator in C and created a .so for CentOS 7.6 and put it in the /user/local/lib folder and the Call Library Function Node worked properly to find the .SO as outlined.
I am about to try the .so on Linux RT
So we have the .so already created, but we weren't able to find any documentation on what to do with it (like where to put it, if we need to decompress it, etc.). Do we just put it in the /user/local/lib folder and delete the older version? i.e. if I have asdf.1.2.3.so and I have asdf.1.2.4.so, do I just put it in there and delete the .1.2.3?