Chained two-wire data bus consisting of two single-wire data buses, each with several differential levels for bidirectional transmission of lighting data based on the JTAG protocol

摘要

Differential four-wire data bus system having a differential two-wire data bus (b1, b2, b3) between a bus master (BM) and a plurality of bus nodes (BS1, BS2, BS3), - each bus node (BS1, BS2, BS3) having a JTAG interface to Comprising control of a drive device (PWM1, PWM2, PWM3) of an electrical load (LM, LM1, LM2, LM3), and wherein the JTAG interface is connected to the differential two-wire data bus (b1, b2, b3) and a test controller (TAPC) comprising a state diagram according to the IEEE 1149 standard and in particular one or more of the sub-standards IEEE 1149.1 to IEEE 1149.8 and their further developments and wherein the one JTAG interface of at least one of the bus nodes (BS1, BS2, BS3) for controlling the drive device ( PWM1, PWM2, PWM3) of at least one luminous means (LM; LM1, LM2, LM3) is provided - illumination data being transmitted via the two-wire differential data bus (b1, b2, b3) and the JTAG interface s at least one of the bus nodes (BS1, BS2, BS3) to the drive device (PWM1, PWM2, PWM3) of the at least one light source (LM; LM1, LM2, LM3).