A vapor compression system including an evaporator, a compressor, and a condenser interconnected in a closed-loop system and a method of operating such a system. The first marking carrier is scanned by a first sensor and a first sensor signal is generated. A lower insulating layer made of silicon nitride and an upper insulating layer made of a photosensitive organic material are deposited thereon after forming data lines and drain electrodes. The decoding unit decodes the output of the first latch unit to correspondingly generate fine code of a first, a second, a third and a fourth codes. The transceiver is designed to electrically isolate the secondary channel from the primary channel.