UT-2209 is a repeater with optoelectronic isolation. It complies with RS-485 standard; it can extend the communication distance of RS-485 BUS network, and increase the quantity of RS-485 network devices. The built-in DC/DC isolated module can provide as high as 2,500Vrm isolated voltage; the fast instant voltage restraint on both sides 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 and ESD 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-485 adopts 2-pin terminal block as input and output. 

This repeater 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 (RTS, DTR); there is no need jumper wire setting for full duplex (RS-422) and half duplex (RS-485) mode, plug & play.

UT-2209 User manual

UT-2209 Datasheet