Single-wire data communications with data storage memory units that may be coupled with a wirelessly energized power supply is enabled in electronic monitoring modules in customer replaceable units (CRUs) such as toner bottles in image forming devices. Communication between modularly designed office equipment and installed CRUs may include data transmission implemented by providing a single point of contact on, for example, a rotational axis at the closed end of a rotating CRU, or by placing a conductive patch, band ring on the periphery of such CRU such that a single-wire data transfer contact is effected with the CRU. A communications link is provided which is not adversely affected by dirt or other foreign objects and is not limited by necessary motion which must be imparted to the CRU for optimum operation in the modular equipment within which the CRU is installed, or other interference that may adversely affects a wireless communications link.