The main function of the TD321S485H / TD521S485H series is to convert a logic level signal into isolatedRS485 diferential level signals. The special integrated IC technology of the RS485 transceiver achievesisolation between the power supply and the signal lines isolation, does RS485 communication andprotects the bus all in one and the same module. The product's isolated power supply withstands a testvoltage of up to 3000VDc. The Products are using pick and place SMD technology, thus enabling the useof fuly automated processing. Also, they can easily be embedded in the user's end equipment, to achievefully functional RS485 network connections.