DOUBLE SYSTEM ELECTRONIC COMPUTER, CONTROLLER USING DOUBLE SYSTEM ELECTRONIC COMPUTER AND RAILROAD SIGNAL MAINTAINING DEVICE

PROBLEM TO BE SOLVED: To provide a double system electronic computer by which the decrease of the activity ratio of a system due to disturbance can be escaped. SOLUTION: A double system electronic computer is constituted so that the output of a one system processing part 111 is fetched by a two system processing part 112 and the output of the two system processing part 112 is fetched by the one system processing part 111, and they are mutually checked. In this case, the one system processing part 111 transmits an output signal 113 as a processing end confirmation signal to the two system at the time of the end of the processing in each control cycle, and the two system processing part 112 receives the confirmation signal 113 and starts a processing in the next cycle, and the two system processing part 112 transmits an output signal 114 as a processing end confirmation signal to the one system at the time of the end of the processing in one cycle, and the one system processing part 111 receives the confirmation signal 114, and starts a processing in the next cycle. Thus, both the systems attain synchronization by software for mutually clocking the other control cycle.