We found (by trial-and-error) that the "tio" command (setting power on ports 0-4 on titans) has at least one port numbering wrong:
tio 2 0; tio 2 1 works for ttyS2 (CSAT)
tio 3 0; tio 3 1 works for ttyS1! (the TRH mote on plain A stations)
We're not sure at this point whether it is a cabling or software issue. We also haven't tested the other ports.