| 摘要 |
PURPOSE:To simplify and economize the execution and control of a program, by adopting such an operation system as alternatively executes the command receiving processing from the maintenance and testing equipment and the switchboard connection processing, in an electronic switchboard. CONSTITUTION:When the electric power supply is turned on, the central control equipment CC detects whether the ground has been supplied or not to the keyboard port KBDPT through the connecting line KCN from the keyboard KBD. When the ground has been supplied, the equipment CC becomes ready for receiving a command CM, the CM information by operating the key matrix KYMTX of the KBD is encoded by the decoder DCR, and it is loaded in the CPU through the key port KYPT of the CC and the data bus control circuit BUSCONT. The CC continues the CM receiving and processing state until the switching connection processing start CM comes in, and when this CM comes in, the CC stops the CM receiving and processing, and starts the switching connection processing. When the switching connection processing is being executed, if the reset key RS is operated, the CPU is reset, and becomes a CM receiving and processing state. |
