Correct. If using just the AIU's ACC port relays, if none of the ACC ports are "ON", the PBW would be generating the blasting out the watchdog signal once per second...but no one would be listening! Oh well. There are bigger problems in the world!
Note that the AIU ACC port internal relays are capable of 3 or 4 Amps (something like that). This should not be a problem for roundtable whiskers, sidings, etc. since you shouldn't be zooming engines with long loads like you might on a main-line section. In which case you'd have the ACC port power an external $1 relay that can handle the "full" 10 Amps for a TIU channel.
