![2554-a](https://www.napa.fr/en/wp-content/uploads/2012/06/2554-A_large.jpg)
2554-A
The 2554-A is an isolated 4-channel high-speed counter input module. Each channel can operate in one of three selectable modes: frequency, period, or general counter. In addition, two channels may be configured together for quadrature mode operation.