I'm not sure what the connection to XML might be, but if you don't have a library that can handle whatever format the file has, you'll need to write a parser based on the java.io classes (like FileInputStream).
As Ulf suggested, you can read the contents of a binary file using FileInputStream. What you should then do with the bytes that you read, entirely depends on what the format of the file is and what your program needs to do with it. Without knowing what the bytes in the file mean, you can't do anything useful with it and nobody can tell you. You should lookup documentation of the device to find out what the format of the file is.