The MGC—40 system is equipped with a user interface VS—100. This VS—100,with an 4.3—inch display, is designed with an explosion—proof box which can be operated outsige the box and is pro rammoblz without keyboard input. And it allows users on site to access all gear traces and it is easy to operate and has Chinese/English options. The VS—100 display control unit can be installed on a local power distribution unit or in a remote location to communicate with the MGC—40 heat tracing controller via an Ethernet or serial interface.