TAC Xenta 421A/422A and 451A/452A I/O Modules Manual

This document describes the TAC Xenta 421A/422A and 451A/452A I/O modules, which extend the existing series by offering 100% universal inputs for installation flexibility and cost savings. The modules feature manual override switches, plug-in electronics for easy maintenance, and are designed for open standard LonWorks systems, supporting backward compatibility and use as certified LonMark devices.