| 摘要 |
<p>PURPOSE:To prevent a user from miscontrolling a camera system without noticing by quitting subsequent communicating operation if the voltage level of a data communication line is abnormal before the start of the communicating operation. CONSTITUTION:This device is equipped with a voltage level detecting means 2 which generates an abnormality signal showing abnormality if the voltage level of the data communication line is abnormal before the start of the data communicating operation and a control part 101 which quits the subsequent communicating operation when the voltage level detecting means 2 outputs the abnormality signal. The subsequent communicating operation after the abnormality is detected is not performed, so control which appears to be normal is not performed. Consequently, even when the control part 2 of the CPU, etc., of a camera main body 1 is so designed that the line for data communication between an external accessory and an internal function unit is used in common, wrong control by the camera owing to wrong data generated if part of the communication line is short-circuited for an external factor is prevented.</p> |
