The invention is a serial bus identification circuit for a module that enables a microcontroller or microprocessor to identify one or many modules, each having an iButton digital device. The invention enables electronic activating and identifying the digital device amongst a plurality of similar devices. Each digital device has a unique digital registration number, and is an element of a module. In addition to the digital device, the module has a dual addressable switch component having a first switch and second switch, where the dual addressable switch component has a unique digital address; a light emitting source; and a source of electrical power. The dual addressable switch component and the unique digital device are in electrical communication with the serial data bus, and can be added as modules. When the first switch of the unique addressable component is closed, the digital device can be accessed, and the unique digital registration number can be down loaded and correlated to the dual addressable switch component. The second switch of the unique addressable component can be closed activating the light emitting source utilizing the source of electrical power. The light emitting source provides an identifying position signal for the device.