| 摘要 |
<p>PURPOSE:To eliminate an influence due to the number of multiple transmission units or the unit, for which a power source is not supplied, and to execute multiple transmission between the respective multiple transmission units by setting a bias circuit to set the potential of a multiple transmission line in the multiple transmission unit, for which the power source is supplied to the multiple transmission line without fail when a multiple signal is in a transmittable state. CONSTITUTION:The bias circuit to set the potential of a multiple transmission line 8 is set in multiple transmission units 3 and 6, for which the power source is supplied to the multiple transmission line 8 when the multiple signal is in the transmittable state, among multiple transmission units 3-7. Namely, for the multiple transmission units 3 and 6, for which the bias circuit is set, the power source is supplied to the multiple transmission line 8 without fail when the multiple signal is in the transmittable state. Thus, according to the key position of an ignition key switch 16, the transmission can be executed simultaneously to the respective multiple transmission units 3-7 without being affetcetd by the multiple transmission units 4, 5 and 7, to which the power source is not supplied.</p> |
