SLASEC8B February 2017 – January 2019 PGA460-Q1
The pulse count determines how many alternating periods are applied to the transducer by the complementary low-side drivers and determines the total width of the ultrasonic ping that was transmitted. The larger the width of the transmitted ping, the larger the width of the returned echo signature of the reflected surface and the more resolution available to set a stable threshold. A disadvantage of a large pulse count is a large ringing-decay period, which limits how detectable objects are at short distances.
Select a pulse count based on the minimum object distance requirement. If short-distance object detection is not a priority, a high pulse count is not a concern. Certain transducers can be driven continuously while others have a limit to the maximum driving-pulse count. Refer to the specification for the selected transducer to determine if the pulse count must be limited.