| 摘要 |
A method for analysis of rotary dial pulses focuses on transitions between pulse levels and differentiates true level changes from noise using a procedure employing two sample counters. One counter registers the number of consecutive samples at either the high or low levels and, once a predetermined number of consecutive samples are detected, a corresponding high or low level is declared. However, since noise may influence the detection, the total number of samples, from the first indication of a level change until the declaration of a state, is maintained in a second counter. A false transition reinitializes both counters, while level changes yielding less than the predetermined number only reinitialize the first counter.
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