Problem: Using our existing 4 to 20mA transmission output to send signals about 40 to 50 meters to the measurement room without having to pay extremely high cable costs. Furthermore, a large number of Temperature Controllers per device (about 25, including 12 for control and 12 for alarms) are required, and space constraint in the heating device control panel. Change the present 4- to 20-mA transmission output to RS-485 for a major education in wiring and labor. Use E5ZN Modular Temperature Controllers to save space.