[Type] is a buffer type that can take one of the following values: Q (constant Q), I (Increment), B (Bragg).
[N] is a number given to a buffer of interest. For example, PI1 will print the contents of increment buffer 1 (I1). Alternatively, the user can use from and to numbers to specify a range of buffers to be printed: PI1-10 will print increment buffers 1 through 10.