The SCI PN-1B is a pulse-code modulation (PCM) databus used for digital communications between sensors and systems in audio and video equipment. The PN-1B is an asynchronous databus using bipolar Manchester coding. It has a 5 wire unipolar cable, with a maximum length of 10 meters and a maximum data rate of 19.2 Kbps. It has support for three optional speed modes: 9.6 Kbps, 19.2 Kbps, and 38.4 Kbps. The PN-1B supports synchronous and asynchronous communications, offering balanced and unbalanced lines with low-voltage differential signaling and a maximum of 32 addressable devices. It is also designed to be compatible with other SCI components, such as the SMPTE 259M “C” Standard.