| 摘要 |
<p>PURPOSE:To detect insertion/extraction without increasing the number of components such as signal lines for new insertion/extraction detection and their terminals by detecting the insertion/extraction by utilizing signal lines for transmitting information between existent functional units. CONSTITUTION:When a functional unit 11 is extracted, the functional unit 11 is disconnected from the signal line which connects the functional unit to a main functional unit 10. The input side of the signal line is opened, the input impedance is varied and an insertion/extraction detection part 3 detects the level variation of the signal line to detect the insertion/extraction. Consequently, a central control processing part 2 is informed of it with an interruption signal. Further, when the functional unit 11 is inserted, the insertion/extraction detection part 3 detects two signal lines 4 having simultaneous transition from ON states to other states. The central control processing part 2 is informed of it similarly to the detection of the extraction of the function unit 11.</p> |
