Calsense CS-2W-POC 2-Wire POC Decoder. The Calsense 2-Wire POC Decoder, model CS-2W-POC operates a single master valve and flow sensor. A single controller can operate up to four Calsense POC Decoders, with a maximum of 12 points of connection in a chain of Calsense controllers using FLOWSENSE® technology. It is recommended that all wire runs between valves and Calsense 2‐Wire Decoders be direct pulls and have no splices except at the Calsense Decoder location.