DATA INPUT/OUTPUT CIRCUIT EXTENSION DEVICE FOR REMOTE I/O SLAVE STATION

PROBLEM TO BE SOLVED: To input/output data among a plurality of input/output circuits using one remote I/O slave station. SOLUTION: Input/output data to be latched by an output word latch circuit 4 of a remote I/O slave station, includes: a line address for an input/output circuit; a command to designate an input/output mode; and multi-bit input/output data. A line address generation circuit 6 determines either a display output circuit 15 or a key input circuit 17 according to the line address or the command, and writes the input/output data into a register 7 or 9. A line address counter 10 designates column data to read the output data of the register 7, and sets the column data to a transistor array 14. Each of a display driver 12 and a key input driver 16 determines the row address of an LED display circuit 15 or a key input circuit 17 by decoding the line address, and carries out matrix driving according to the column data and the row address. COPYRIGHT: (C)2011,JPO&INPIT