Hi There - we connect control devices to copiers all the time so are pretty familar with the out puts - although they do differ from model to model but generally they put out a 5vdc signal while something like colour or A3 is selected and every time a piece of paper passes the exit sensor the copier outputs a 24vdc pulse. So for example if you did 10 copies it will put out a pulse as each copy passes this sensor. Copiers have a standard plug with this count pulse as most are designed to cater for controllers being fitted
regards
Dave