Littelfuse CIO-777-PR Communications ModuleLittelfuse CIO 777 PR Product Communications Module Description The CIO 777 PR module is a convenient, cost effective Profibus interface device capable of providing discrete control and monitoring of motor starters, drives and other devices over a Profibus network. The CIO 777 PR module provides four solid state 24VDC inputs and two AC DC rated relay outputs. It can function as a stand alone I O device or can be connected to any model 777 P series