Fanuc Corporation

Motoyoshi Miyachi

Yasushi Nomoto

Masuo Kokura

A PLC system includes a plurality of I/O devices each connecting a control target of each of a plurality of PLCs to each of the plurality of PLCs, and a PC. Each one of the plurality of PLCs stores first output data obtained by executing a self-assigned program to control the control target connected to each PLC, and stores second output data obtained when the PC or another PLC executes another program allocated to the PC or the other PLC to control the control target connected to the one PLC. Each of the plurality of PLCs outputs one of the first output data and the second output data to the I/O device connected to each PLC based on selection information transmitted from the PC.

Controller system and control method

A programmable controller for executing a sequence program comprises a processor for reading and executing an instruction code from an external memory, an instruction cache memory for storing a branch destination program code of a branch instruction included in the sequence program, and a cache controller for entering the branch destination program code in the instruction cache memory according to data on priority, the instruction code of the branch instruction including the data on priority of an entry into the instruction cache memory.

Programmable controller

A programmable controller which executes a plurality of independent sequence programs in parallel is provided with an ASIC, including a plurality of arithmetic-logic units and a plurality of arbitration circuits, and MPUs as many as the arbitration circuits. The entire execution time of the programmable controller is shortened by changing combinations (groups of arithmetic-logic units) of the MPUs (and the arbitration circuits as many as the MPUs) and the arithmetic-logic units, based on the ratios of MPU execution instructions and ASIC execution instructions included in those instructions which constitute the programs to be executed in parallel.

Growing community of inventors

Minamitsuru-gun, Japan

Motoyoshi Miyachi