摘要 |
A signal persistence time interval recognition system reproduces a condition of an input signal as a condition of an output signal only when the input signal condition persists for at least a predetermined time interval. The system periodically scans the input signal condition and has a first memory (ROM) for storing a start value indicative of the time interval. A second memory (RAM) stores a value indicative of the time counted since the detection of a difference between the input and output signal conditions. A third memory stores the output signal condition and a processor brings the start value from the first memory into the second memory when no difference is detected. The processor modifies the value in the second memory each time such a difference is detected and until a value is reached indicating that the time interval has been counted, the output signal condition in the third memory being then changed. The first memory only stores a single start value for all conditions of the input signal and the processor perform the modification in the second memory independently of the first memory. |