HEMSA-T-031 industrial-grade PCI-E to RS-485/422 multi-serial card is compatible with RS-485 and RS-422 standards. It can convert single-ended PCI-E signals to balanced differential RS-485/422 signals with fast transient voltage suppressor protector, which is designed to protect RS-485/422 interface with today's advanced TVS (TRANSIENT VOLTAGE SUPPRESSOR) . The TVS tube is in a high resistance state under normal conditions. When the two ends of the TVS tube are subjected to an instantaneous high energy shock, the tube can reduce the impedance of its two ends at a very high rate and absorb large current, thus clamping the voltage at its two ends to a pre-determined value and protecting the circuit components behind it from being damaged by transient high-voltage shock and damage. This protector can effectively suppress lightning and ESD, providing 600W of lightning surge protection power per wire, as well as surge voltages and transient over-voltage generated by various causes on the wire. The extremely small inter-pole capacitance ensures high-speed transmission of the RS-485/422 interface.