USB to RS485 Converter Description:

USB to RS485 Converter USB to RS485 Adapter,CH340E USB to TTL

RS485 connector: to your RS485 device

No need external power, powered by USB port

Fully compliant USB 2.0 standard , backward compatible with USB1.1

All kinds with RS485 port device parameter settings, data communication.
LED display of communication data.
Machine PLC data reading and writing.
Monitoring data read and write, and PTZ control.
Centralized control of household electrical appliances.
Access Control System card.

USB to RS485 Converter Specification:
Support System: Windows XP , Vista, Windows 7/8

Supports baud rate range : 75bps – 115200bps , up to 6Mbps

Supports Plug , Play and hot-swap (USB side)

Better than using CH340E chip or similar chip to support the laptop USB port .

Communication distance up to 1.2KM, with anti-jamming performance of industrial site ;

Work temperature range: -40C ~ +85C

Communication distance :1200m(max)

Dimension:6.1×1.6×1.3cm

Color: Black en.wikipedia.org
RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. It is generally accepted that RS-485 can be used with data rates up to 10 Mbit/s or, at lower speeds, distances up to 1,200 m (4,000 ft). As a rule of thumb, the speed in bit/s multiplied by the length in meters should not exceed 108. Thus a 50-meter cable should not signal faster than 2 Mbit/s.