System-S Serial RS232 to RS422 / RS485 Converter Converter Adapter. Convert from RS232 to RS485 or RS422 Transmission speed: 300-115.3Kbs Working range: -25 ~ 70 degrees Celsius temperature, 0% ~ 95% relative humidity Supports automatic detection and manual switching of RS422 and RS485. EIA-232 to EIA-485 specifications (with external power) Transmission distance: 1200 meters (RS-485 connector); 5 meters (RS-232 connector) Working method: Asynchronous full duplex, half duplex automatic selection, no jumper setting required. TTL Transmission media: shielded twisted pair or lines.