Allen-Bradley 1771-HS3CR PLC5 3-Axis Servo Controller Module By wayne No Comments on Allen-Bradley 1771-HS3CR PLC5 3-Axis Servo Controller Module 2 Min Read Buy the Allen-Bradley 1771-HS3CR 3-axis servo controller module for your PLC5 system. It provides precise motion control with a 250 KHz encoder input.