Although it makes sense to update to the newest firmware, this will not make any difference as far
as connectivity is concerned. An older firmware will still work for the TS-480.
I am really not sure what you are trying to do. Hooking up a serial cable won't make it work at all,
it needs ethernet connectivity to work. The serial cable must go between the RRC the rig's CAT port.
I suspect that you may have a wiring problem somewhere, please look at the manual. Another common
problem is that the RJ-11 cables used must have all wires connected. In other words, you can not use a
standard telephone cord, it must be a "3-line cord" or make the cable up yourself. The U.S. version of the
TS-480 ships only with one cable (the manual is wrong), so you need to make sure you get a correct
second cable. This may be your problem.
73,
Mitch DJ0QN / K7DX