| 摘要 |
PURPOSE:To realize switching of the address to self-diagnosis and returning to the original place under the control of a CPU., by providing a means to deliver the proper and common addresses to plural input/output devices connected to a serial line. CONSTITUTION:Serial data is supplied to an input/output device to be connected to a serial line from a CPU through a serial line 6. Thus each input/output device receives the data only when coincidence is obtained between the address of the data and the address of the corresponding input/output device. In case the contents of the data are identical with the data by which the device address is switched, an FF5 is set to switch 4 the own device address to an address output circuit 3 which is common to all devices. The CPU gives an instruction to each input/output device to switch the address successively. When all input/output devices have the same common address, the data is transferred among the input/ output devices with no intervention of the CPU to perform self-diagnosis. Then the CPU gives an instruction to return the address of each input/output device to the original place when the self-diagnosis is over. |
