When in the printing process, sometimes the products miss printing？

1)The photocell has not been installed well. Change the installation position of the photocell, and make sure that in the continuous product movement, every product can be sensed by the photocell; Exclude the influence of color to the photocell.

2)The sensitivity of photocell has not been adjusted well. Adjust the potentiometer of the sensitivity of photocell. The right adjustment is that when the photocell has an inductive signal, the corresponding sensor light is on.