Abstract: A device which mechanically records, accumulates and stores events such as the consumption of water, gas or electricity, and which, on command, transmits the stored information in serial, digitized form. A series of optically coded storage wheels representing respective decimal columns are driven by a water meter or the like and are geared together such that each adjacent pair of wheels rotates in a one to ten ratio. Each wheel includes a set of binary coded discs which may be optically scanned to provide data as to the instantaneous position of the wheel and thus the cumulative total of the usage of water. The scanning operation is performed by a diode and photocell assembly which is serially scanned past the wheels in a manner such that a light beam is interrupted in a pattern conforming with the rotative positions of the storage wheels. The photocell senses the light interruption pattern and transmits a pulsed signal that contains the desired information.