In 2003, a vacuum system controller-VAC400 was developed in IMP COMLAB which is based on a Mixed signal processor MSP430F149 from Texas Instruments, the different kinds of vacuometers can be connected to VAC400, the data, commands and status of the vacuometer can be monitored and controlled remotely via 4-wire RS-485 series bus and intranet. The controller has following main functions (shown in Fig.l).