Rvfm logic probe rvfm lp 2800 p this logic probe has a memory function which can detect the occurrence of single pulses or logic level it can detect one shot and low repeat rate narrow pulses which are nearly impossible to see even with a fast scope with this probe they are easily detectable and visible p p the probe has three leds red for high logic level green for low logic level and yellow for pulse the intensity of the pulse led is directly proportional to the duty cycle of th