Chapter 2Extensions to LabVIEWLabVIEW LEGO MINDSTORMS NXT Module2-38ni.com•RTM—Built-in Try Me programs•RIC—Image (graphic) files for use with the NXTDrawGraphic system call method in RXE programs•RSO—Sound files•SYS—Internal NXT firmware files•CAL—Sensor calibration file•TXT—ASCII text file using CR/LF (Windows) end-of-line convention•LOG—ASCII text file created by NXT dataloggingWhen manipulating files with a program, you can create, modify, rename, or delete any file in the system. Typical NXT programs use simple text files with the TXT extension. You then can upload these files easily to a PC, which then can read the files. You can use any extension or file encoding you choose, but make sure not to interfere with the various files that the NXT firmware and other programs use.The default NXT firmware configuration includes several built-in files. You can delete any of these files to free up space, but you lose any associated functionality until you restore these files.To manipulate files, wire an NXTSyscall refnum to any Invoke Node, then choose a method beginning with NXTFile. The following sections list these individual methods along with some method concepts.