is also limited by noise, and the local jitter of the AC line's zero crossing. The high reliability comes from its reliable timing system (i.e. zero crossing), high signal to noise ratio (frequencies are chosen to avoid common power line noise), lack of intermodulation distortion, and adaptive signal detection.

The most significant bits are sent first, unlike a conventional serial port. The data from zero crossings should be collected into 8-bit bytes. Each byte is collected into 42-byte packets. The