| 摘要 |
<p>PURPOSE: To electrically confirm the connection state of an optional device by providing a means for detecting the transmission impossibility of a processing request to the optional device. CONSTITUTION: Control parts 10 and 20 and memory parts 11 and 21 for constituting an information processing system are connected through a common bus 4 and are constituted so as to access each other through the common bus 4. On the side of this information processor 1 or the optional device 2, the device address of the optional device 2 is stored as information for confirming the connection state in the memory parts 11 and 12 of the present and opposite devices. The control parts 10 and 20 of the information processor 1 or the optional device 2 periodically call and compare the information for confirming the connection state. As the result, at the time of detecting non-coincidance, the connection abnormality of the optional device 2 is recognized and the operation of the optional device 2 is stopped or the power source of the optional device 2 is turned off.</p> |
