Converts RS-232 to RS-422 or RS-485. 2,000 Volts two-way optical isolation protects devices from power surges, spikes and more. Switchable modes support 2-wire RS-485, 4-wire RS-485, and full-duplex RS-422. DB9 female RS-232 input. Features removable terminal blocks and external power (10-48 VDC).