| 摘要 |
PURPOSE:To reduce the volume of data to be stored in a memory to make it possible to use a small capacitance memory by detecting a no-signal period and storing a no-signal period data in case of converting an analog signal into a digital one and storing the digital signal. CONSTITUTION:When the level of an analog signal from an input terminal 1 is supervised and a no-signal detecting signal is outputted from a no-signal detecting circuit 8, a control circuit 4 keeps the address of an address specifying circuit counted-up status by one and an AND gate is closed and an AND gate 13 is opened through an inverter 10. Consequently an output from an AD converter 2 is not inputted to a memory 3 and a no-signal period data is inputted and stored in the memory 3. By adopting a system to record the no-signal period data without AD conversion and recording of the input signal of the no-signal division, the volume of data to be stored in the memory is reduced and the small capacitance memory can be used. |
