Problem

To use Micrologix 1400 (1766-BXB, 1766-BXBA…) built in high speed counters, you need to setup the followings:

Setup of High Speed Counter

  1. Enable high speed counter in Controller -> Function Files

    ML1400 High Speed Counter Setting
    ML1400 High Speed Counter Setting
  2. Change input filter from default (8ms for 63 Hz) to whatever filter is suitable. The number shown is shown for ON then OFF. So a 0.005ms is suitable for 100 kHz (1 / [5*10^(-6) + 5*10^(-6)]). If you leave it at default filter, inputs can not handle any state change with frequency higher than 63 Hz.

    ML1400 High Speed Counter Filter
    ML1400 High Speed Counter Filter