i would like to know whether i should set the counter to count the pulses whenever ther's no reflection ie distinguishing the 2 targets based on the pulse width or try to count the number of pulses and neglect the width.One of the retro-reflector will have 5 pulses and make the other with 10 pulses.In this case i think i will need to set the delay to scan through the reflector completely and then a long delay before obtaining the other relfector.still confused how to go abt the work.