Pulse Coincidence Counter

[mhoffmann10]

I am trying to build a coincidence counter that takes inputs from two different pulse trains and then increments a value when the pulses coincide in time.  I have found example code to increment correctly on each pulse from a function generator and I have succesfully hooked that up to two different counters, although I am having trouble with determinening when they fire at the same time to increment my third counter.

[johnsold]

Coincidence counting can be difficult. What is the width of the pulses? What is the minimum timing to define coincidence? What is the pulse rate? How many of these parameters are variable? 

Unless the pulses are fairly wide and the repetition rate fairly slow, you may need some external logic circuits to determine coincidence. The output of those circuits can be connected to the counter.

Lynn