Oh look, its the yearly thread about how silly the pneumatics rules are when it comes to pre-charging your tanks.
My stance is unchanged.
1) You are allowed to pre-fill your tanks, regardless of whether or not your robot has the compressor on board.
2) You are allowed to change your battery AFTER you pre-charge the tanks and BEFORE the start of a MATCH.
3) If you have the compressor off-board, for some inexplicable reason, you have to power and control it via the cRIO, rather than some other system that safely shuts off at 120psi and would otherwise meet pneumatics rules (particularly in terms of safety features).
#3 is the one I don't understand. Since #1 and #2 are true, it literally makes no difference to a match HOW the air got in the tanks. There are dozens of ways I can think of to safely control my compressor that don't involve me needing some way of attaching it to the cRIO (and ostensibly, through a Spike and DSC and PDB)
Relevant 2014 rules here:
http://frc-manual.usfirst.org/Search_Results/off-board