A secondary (CHILD) 4XE file can be saved to the microSD card and called from the Main program that resides in the FLASH. Once loaded, a child 4XE file takes full control and runs from the RAM.
When you reach “Exit” in the 4XE file code, the module goes back to the start-up routine returning control to the Main Program in FLASH, in effect restarting it.
You can pass arguments to a 4XE file from the Main Program. The 4XE File cannot return anything to the Main program.