Note that a full document will eventually appear. The purpose here is to get early users going with their experiments. This is taken care of in the IFLO.tcl file that is sourced when you fire up aocontrol, so you need not worry about it. ABPP will always choose the largest bandwidth possible given the RF and the DM of the pulsar. The dispersion smearing across a channel cannot be larger than the channel bandwidth.
Any center frequency is possible at any of the receivers.
No cabling is required to run the machine which should always be switched on. This is a very useful sanity check. If you wish to turn it off sooner merely use the 25 Hz cal toggler on the master gui.