| 摘要 |
PROBLEM TO BE SOLVED: To provide an expandable parking lot in which the presence states of many vehicles can be detected by a constitution of a simple wiring and a low cost, a disconnection portion can be easily specified at the time of generation of a disconnection and quickly restored from the disconnection. SOLUTION: A sensing unit 1 outputs a shift pulse SEL to sensor units 2 connected in series and a sensor unit 2 outputs data DATA of present vehicles and an error check signal Err CHK to the sensing unit 1 via a common line for a period when the sensor unit 2 holes the SEL. The SEL is successively transferred to the sensor unit 2 of a poststage, and the sensing unit 1 performs a time division for the DATA and Err CHK and is capable of detecting each of them. By the DATA, the turning on/off display on a display panel is performed for the presence of vehicle state. At the time of the abnormality of the Err CHK, the flickering display of the state is performed. |
