UT-2216 is a converter which complies with RS-232C, and RS-485 standards; it converts single side RS-232 signal to a balanced differential RS-485 signal. The fast instant voltage restraint is designed to protect RS-485 interface; it adopts advanced TVS (TRANSIENT VOLTAGE SUPPRESSOR) instant voltage restraint; normally, TVS tube is in high impedance state; when both sides of TVS tube suffer from high power impact in a sudden, the voltage restraint will fast lower the impedance from both sides, and absorb in big current; with this, the voltage on both sides are fixed at presupposed value, protects the component of circuit from damage. This voltage restraint provides 600W each wire with lightning protection, and surge voltage and instant overvoltage protection on circuit which causing by all reasons; the tiny interelectrode capacitance ensures high speed transmission for RS-485 ports. RS-232 port connects with RS-232C standard port by DB9 female connector; RS-485 adopts RJ-45 and 4 bits terminal block as output. This converter is with built-in zero delay auto receiving and transmitting conversion and unique I/O circuit auto control data flow direction without any handshake signal (RTU, DTR); there is no need jumper wire setting for half duplex (RS-485) mode, plug & play. It is compatible with current communication software and hardware, no need to set the previous working mode which base on RS-232. UT-2216 converter provides connection for point to point, point to multipoint communication. For point to multipoint mode, each converter is allowed to connect 32 sets RS-485 devices with baudrate 300-115.2Kbps. The power and data flow indicators indicate the working status.