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USB485i - USB to RS485 Serial Converters

Most current Desktop and Laptop PCs do not have serial ports as standard but all have USB ports. The USB485i provides a compact and cost effective solution to safely interfacing PCs to RS-485 networks.

The USB485i RS485 converters have big advantages over traditional methods of accessing RS485 networks from PCs.

  • The converters take their power from the PC's USB port and therefore require no external power supply.
  • The USB485i is fully opto-isolated giving valuable protection to the PC in harsh environments.
  • They are ideal for use with RS485 two wire networks
  • Consistent supply
  • JOSCAR Registered Supplier
USB485i - USB to RS485 Serial Converter

Having no external power supply is a big advantage in portable and industrial applications, this is achieved by drawing all the power required by the converters from the PC's USB port. The devices are USB 1.1 specification full speed (12 mbits/second) compliant. This means they will work when attached to USB 1.1, USB 2.0 or USB 3.0 ports.

The USB485i is designed to isolate the serial communications from the computer power. In fault conditions they are protected to sustain common mode voltages up to peaks of 1KVdc. This isolation can be used in serial communications systems where high integrity data transmission and reception are required in an electrically severe environment.

Another big advantage of the USB485i is that it can automatically enable the RS485 transmitter when data is to be transmitted. This allows it to support two wire, half duplex communications without any need to control the RS485 transmitter enable from the application program. In short an application program written to support RS232 comms with no flow control can be made to interface to RS485 without modification.

Each of the USB485i devices come with Windows and Mac OS compatible drivers and are designed to meet stringent performance requirements and be easy to use while maintaining compatibility with standard serial communications boards. The devices are also supported by Linux, FreeBSD and OpenBSD. The Windows drivers are compatible with LabVIEW standard serial driver interface (NI VISA).

We have been producing these converters based on FTDI technology, for over 15 years and have supplied major projects in Civil Engineering, the Military, Aerospace, and Nuclear Industries. The consistency of supply has been a key factor in customers choosing our products.

USB485i manual

Key Features

  • Interface new PCs and laptops to existing RS485 or RS422 networks
  • USB Bus Powered - no external power supply required
  • Full optical isolation
  • Two wire, half duplex communications without RS485 transmitter enable control from application program
  • Windows drivers from Windows 98 to Windows 10
  • Mac OS-8/9/X drivers
  • Native support in Linux kernel 2.4 and later ('ftdi_sio' driver)
  • Native support in OpenBSD 3.2 and later and FreeBSD 4.8 and later ('uftdi' driver)
  • Windows CE.NET (4.2 or later) drivers for x86 and ARM/XScale processors (USB host controller required)
  • Support for non-standard baud rates
  • Fast USB to RS485 with data rates up to 3M baud
  • FIFO modes supporting a 384 character receive buffer and 128 byte transmit buffers.
  • Three point isolated serial communications
  • Industry standard 9 way connectors
  • RS485 Full Duplex, Half Duplex, Multi-drop applications
  • RS485 transmitter enabled automatically in Half Duplex mode
  • Full specification signal levels
  • Low power consumption
  • RoHS compliant

For information on the range of baud rates supported see Supported Baud Rates for USB232U and USB485Ui.

To order USB serial converters please: Buy USB232 USB to RS232 Converter
or e-mail: Pat Marsh
For more information please e-mail: Dave Cooper

USB to Serial Converters

MEV's fast USB to serial converters provide legacy RS232 or RS485 serial communication interfaces to computers with USB support.

USB232    high speed USB RS232 interface.
USB485i    opto-isolated USB RS485 interface.