Sampling interval. It is a floating-point number inversely proportional to the width of the main sinc lobe. That is, the smaller the sampling interval, the wider the main lobe; the larger the sampling interval, the smaller the main lobe. Notice that when delta t is 1, and delay is an integer value, the node sets sinc pattern to zero except at the point where i = delay. At this point, the value is equal to amplitude. The recommended range of values for the sampling interval is 0 < delta t < 1. delta t must be greater than 0.0. If delta t is less than or equal to zero, the node sets sinc pattern to an empty array and returns an error.