When a single pulse only is input in the Counter, why does the Counter convert the pulse into at least two?

The following two causes may be causing in this problem.

1. The maximum counting speed setting is set to high-speed response and the Counter may be receiving relay chattering, bouncing, or noise input.

Countermeasure:

Set the maximum counting speed to as lower speed.

2. If the Counter has a prescaling function, the prescale value may be set.

Countermeasure:

Check whether the prescale value is set.