Communication bus system operable in a sleep mode and a normal mode

Communication bus system comprises multiple node circuit (10a-d) and coupling circuit (10a-d) trunk circuit (12,14,16). The trunk circuit (12,14,16) with a (10a-d) and node circuit relays the information (21) receiver sensor circuit is a normal condition (124,164). The digital sensing circuit (124,164) is blacked part in the sleep mode. Detection circuit (120,160) when the trunk circuit (12,14,16) are sleep mode detection input information (41). Mode control circuit (122,162) for vehicle information input (21), detecting and receiver sensor (124,164) power-on. And the step to ensure that the information (21) is normal condition is relayed in the form is un-re-changeable program. The sound control circuit (122,162) is arranged is made of the receiver sensor (124,164) relay information input (21) remainder of the power-on (25). Power in one embodiment, a power supply (30) controls power supply voltage of normal condition, slave power supply (30) capacitor (306) consumption transmission information input (21) remainder (25) matched. In one embodiment, a detecting circuit (120,160); the normal condition time replacing the other detector of normal control manipulation direction (58a-d) and receiver sensor (124,164) manipulation direction of the normal condition temporarily.