Even though both of these technologies use the AC power line to
transmit their information, they are completely
incompatible with each other. However, they can
co-exist on the same powerline. In fact,
transmissions from both technologies can occur
simultaneously on the powerline, and they will not
interfere with each other.
X10 uses 1msec pulses at a
fixed frequency of 120kHz. These pulses are timed
to begin at the zero crossing of the AC sine wave.
If there is any noise on the powerline at or around
120kHz, the X10 signals could be corrupted.
Information is transmitted at a speed of 120 bits per
second. A typical full X10 command will take a
little under 1 second to complete. (783.33msec)
UPB uses a large single spike on the powerline, each
half cycle. The position of the spike on the
AC sine wave determines
its value. (Pulse Position Modulation) Information is transmitted faster than
X10, at a speed of 240 bits per second. Even
though a typical UPB command contains more information
than an X10 command, it is still transmitted faster.
Approximately 300 msec for a typical command.
