... , synchronous, uncompressed, distortion-free transmission. Audio Features: Number of Channels: 4 Audio input/out impedance: 600Ω(unbalanced/balanced) Audio input/output ... reversed RS485 Date, FC interfaceJY-4V4A4D 4 Channel Video + 4 Channel duplex Audio/ Date, FC interfaceJY-4BV4A1D 4 Channel duplex Video / Audio + 1 ...