Electronic devices such as CFL or LED lights and small modular power supplies can inject noise onto the powerline. As we add more of these devices to our homes, many of us are experiencing problems with our X10 systems from powerline noise.
X10 commands are sent as a series of signal bursts coupled to the powerline. Presence of a burst signifies a logic “1”, and absence a logic “0”. Noise near the X10 carrier frequency can fill in those blank frames. That can make it impossible for a receiving module to decode commands unless it includes some form of AGC to raise its detection threshold above the noise level.
In the past the only way to deal with powerline noise was to isolate the offending devices with X10 filters. With CFL and LED lights proliferating, that can be cumbersome. The XTB-ANR (Active Noise Reducer) offers an alternate solution. It can even significantly reduce in-band powerline noise.
The XTB-ANR continually monitors the powerline for PLC signals, and will switch off its attenuator when it recognizes an X10 or Insteon signal. One plugged into each phase near the distribution panel will significantly reduce the overall noise levels throughout the home, including any coming in over the utility feed. If there is a known strong noise source inside the home, best results may be obtained by plugging a XTB-ANR into the same circuit. In some cases it may still be necessary to isolate a particularly strong noise source with an individual filter for nearby X10 devices to work properly. The goal is to restore the relatively benign electrical environment that existed when the X10 protocol was first developed.