Application of CPLD and MSP430 MCU in guided wave radar level meter

Guided wave radar level meter is a high performance level meter which makes use of the time domain reflectometry principle.In order to achieve the high-precision time difference measurement system,the circuit design of CPLD working together with MSP430 MCU is used.CPLD is the core of signal transceiver module,it provides trigger signal for narrow pulse generating circuit in the transmitter circuit,it controls the programmable delay device AD9500 in the receiving circuit and achieves equivalent time sampling which changes high-frequency echo pulse signal to low-frequency signal.Signal processing module based on MSP430 calculates level information according to the signal comes from signal transceiver module,and outputs level information using 4~20 mA signal and serial.MSP430 also controls peripheral devices such as LCD screen,keypad and so on.The actual experiments show that the work status of each module of the system meets the theoretical analysis.