Multifunctional signal expansion device

The utility model discloses a multifunctional signal expansion device, which relates to a signal expansion device, and aims to solve the problems that an existing signal expansion device cannot randomly change the types of input and output signals and cannot randomly change the number of the output channels. A processing circuit comprises a clock unit, a communication unit, a CPU and an isolationpower supply. A clock signal output end of the clock unit is connected with a clock signal input end of the CPU, the CPU communicates with the outside through the communication unit, and the isolationpower supply supplies power to the input conversion circuit, the CPU and the output conversion circuit; the signal output end of the input conversion circuit is connected with the signal input end ofthe CPU in a pluggable mode, and the N signal output ends of the CPU are connected with the signal input ends of the N output conversion circuits in a pluggable mode one by one. The multifunctional signal expansion device is s