ROBERT DALE MCCULLOUGH, DO
Osteopathic Medicine at 75 Pl, Tulsa, OK

4992774, Feb 12, 1991

Jan 27, 1989

7/302663

Robert K. McCullough - Tulsa OK

H04M 1104

340310A

A novel way of powering a remote visual display and allowing data interchanges over the same wire pair. Such a station may be used for displaying the time, paging a person or an advertising message. The wire pair that powers a remote visual display also carries the electrically encoded message signal. On the same wire pair there is provision for the master message input station to exchange data with slave message input stations without message collision. Information from an input station key pad is captured by the microprocessor which converts the message to a serial binary signal. This signal drives a power transistor which converts a full wave rectified a. c. power current to a pulse width modulated signal which drives the wire pair connected to a remote visual display. The remote visual display power supply rectifies these signal pulses for power to drive the control circuits and display mechanism (light sources or light reflectors) and decodes the pulse width for display message information. The master message input station uses the time between pulses to exchange data with the slave message input stations.