Control Techniques UD51 ISS4 2ND Encoder option ModuleControl Techniques UD51 ISS4 2nd Encoder Option Module The Control Techniques UD51 ISS4 module is a plug in expansion designed to enable a second encoder input for Unidrive series drives. It provides advanced feedback control options, enabling dual encoder operation and simulated encoder signal outputs for enhanced motor control precision. Key Specifications Model: UD51 ISS4 Function: Second encoder interface option module Encoder Support: Quadrature