If the line power to the UPS were shut off,
would update the screen with:
DTR = Cleared
RTS = Set
CAR = Low ( )
CTS = High (*)
DSR = Low ( )
RNG = Low ( )
indicating that the CTS line had changed status and that the new
status of the CTS line is HIGH.
is valuable in determining the parameters to use in genpowerd.h with
unfamiliar cables and UPSs. In the example above, it could be determined
that RTS probably provides power to the cable and that CTS is the line that
shows changes in the line power's status (with LOW being the normal status
of the line).
If your UPS supports an inverter shutdown, either RTS or DTR could be used to
kill the inverter. Tests should not be performed if your system is using the
UPS. Specifically, the use of the
options together is not recomended.