Abstract: A locator system comprising a number of unique portable IR transmitter units, each having a unique identity address consisting of a 16 bit data stream with two start bits and a stop bit, a number of fixed IR receiver units, each having a unique identity, and a central data processing computer. The transmitter units transmit in the vertical direction and in the horizontal direction simultaneously. Both the transmitter units and the receiver units contain programmable microprocessors, enabling the transmitter units to be addressed with one of up to 65,535 possible identities and enabling the receiver units to store multiple transmitter unit identities until polled by the data processing computer.