| 摘要 |
A microprocessor-controlled light screen comprises a plurality of light transmitters and light receivers arranged in a holder on one side of the screen opening, and a corresponding number of light receivers and light transmitters arranged in a holder on the opposite side of the screen opening. Mutually opposite light transmitters and light receivers are sequentially actuable in pairs from a data processor over a given period of time. The light screen is characterized in that the data processor for each light transmitter and light receiver respectively is programmed to transmit a train of light pulses (codes) and to receive and change the received codes and to re-transmit the changed code to a receiver on the opposite side. The data unit on one side functions as a Master, and on the other side as a Slave. The data units are programmed to change (invert) received codes, and to transmit the changed codes to the opposite side. |
