The UT-520 is an industrial-grade high-performance optical isolation data repeater that is compatible with EIA/TIA-485 standards. It can extend the communication distance of the bus network and increase the number of network devices. The built-in optical isolator and isolation module can provide a high isolation voltage of up to 2500Vrms. The interface has two fast transient voltage suppression protectors that can effectively suppress lightning, lightning and transient overvoltages caused by various reasons on the line, and the extremely small inter-electrode capacitance ensures the high-speed transmission of the interface.