| 摘要 |
PURPOSE:To guarantee desired recognition and discrimination by detecting modification and abuse by providing an AND circuit. a HAND circuit a means to input a test signal, and a means to decide the presence/absence of disconnection of a connecting line. CONSTITUTION:Each terminal of an input/output connector 4 is connected to each input terminal of the AND circuit 5 and the HAND circuit 6 in parallel. Furthermore, this device is constituted so that the test signal of L or H can be inputted simultaneously from a test signal generating part 8 to each terminal of the input/output connector 4. The output of the AND circuit 5 and that of the HAND circuit 6 are issued as L and H alternatively at a prescribed timing (synchronizing with the timing of the test signal) in a normal operation, and also, both outputting states are set with negative (inverted) phase, however, when the disconnection of the line occurs even partially, the case where both output are set with the in-phase occurs. and also, when the output at every circuit 5, 6 is remarked, L and H are inverted in the circuit on one side, however, L remains in the circuit on the other side. Therefore, the presence/absence of such phenomenon is detected by an abnormality decision part 7. |
